Proton-binding polymers for oral administration

ABSTRACT

Pharmaceutical compositions for and methods of treating an animal, including a human, and methods of preparing such compositions. The pharmaceutical compositions contain crosslinked amine polymers and may be used, for example, to treat diseases or other metabolic conditions in which removal of protons and/or chloride ions from the gastrointestinal tract would provide physiological benefits such as normalizing serum bicarbonate concentrations and the blood pH in an animal, including a human.

This application is a continuation of U.S. application Ser. No.16/002,269 filed on Jun. 7, 2018; which is a continuation of U.S.application Ser. No. 15/715,934 filed on Sep. 26, 2017 and issued asU.S. Pat. No. 9,993,500 on Jun. 12, 2018; which is a continuation ofSer. No. 14/944,844 filed on Nov. 18, 2015 and issued as U.S. Pat. No.9,925,214 on Mar. 27, 2018; which is a continuation of U.S. applicationSer. No. 14/311,852 filed on Jun. 23, 2014 and issued as U.S. Pat. No.9,205,107 on Dec. 8, 2015; which is a continuation of InternationalApplication No. PCT/US2014/041152, filed on Jun. 5, 2014; which claimspriority to the U.S. provisional application 61/831,445, filed on Jun.5, 2013, the entire contents of which are hereby incorporated byreference herein in their entireties.

The present invention generally relates to proton-binding polymers fororal administration that may be used in the treatment of metabolicacidosis.

Metabolic acidosis is the result of metabolic and dietary processes thatin various disease states create a condition in which non-volatile acidsaccumulate in the body, causing a net addition of protons (H+) or theloss of bicarbonate (HCO₃ ⁻). Metabolic acidosis occurs when the bodyaccumulates acid from metabolic and dietary processes and the excessacid is not completely removed from the body by the kidneys. Chronickidney disease is often accompanied by metabolic acidosis due to thereduced capacity of the kidney to excrete hydrogen ions secondary to aninability to reclaim filtered bicarbonate (HCO₃ ⁻), synthesize ammonia(ammoniagenesis), and excrete titratable acids. Clinical practiceguidelines recommend initiation of alkali therapy in patients withnon-dialysis-dependent chronic kidney disease (CKD) when the serumbicarbonate level is <22 mEq/L to prevent or treat complications ofmetabolic acidosis. (Clinical practice guidelines for nutrition inchronic renal failure, K/DOQI, National Kidney Foundation, Am. J. KidneyDis. 2000; 35:S1-140; Raphael, K L, Zhang, Y, Wei, G, et al. 2013, Serumbicarbonate and mortality in adults in NHANES III, Nephrol. Dial.Transplant 28: 1207-1213). These complications include malnutrition andgrowth retardation in children, exacerbation of bone disease, increasedmuscle degradation, reduced albumin synthesis, and increasedinflammation. (Leman, J, Litzow, J R, Lennon, E J. 1966. The effects ofchronic acid loads in normal man: further evidence for the participationof bone mineral in the defense against chronic metabolic acidosis, J.Clin. Invest. 45: 1608-1614; Franch H A, Mitch W E, 1998, Catabolism inuremia: the impact of metabolic acidosis, J. Am. Soc. Nephrol. 9:S78-81; Ballmer, P E, McNurlan, M A, Hulter, H N, et al., 1995, Chronicmetabolic acidosis decreases albumin synthesis and induces negativenitrogen balance in humans, J. Clin. Invest. 95: 39-45; Farwell, W R,Taylor, E N, 2010, Serum anion gap, bicarbonate and biomarkers ofinflammation in healthy individuals in a national survey, CMAJ182:137-141). Overt metabolic acidosis is present in a large proportionof patients when the estimated glomerular filtration rate is below 30ml/min/1.73 m². (KDOQI bone guidelines: American Journal of KidneyDiseases (2003) 42:S1-S201. (suppl); Widmer B, Gerhardt R E, HarringtonJ T, Cohen J J, Serum electrolyte and acid base composition: Theinfluence of graded degrees of chronic renal failure, Arch InternMed139:1099-1102, 1979; Dobre M, Yang, W, Chen J, et. al., Associationof serum bicarbonate with risk of renal and cardiovascular outcomes inCKD: a report from the chronic renal insufficiency cohort (CRIC) study.Am. J. Kidney Dis. 62: 670-678, 2013; Yaqoob, M M. Acidosis andprogression of chronic kidney disease. Curr. Opin. Nephrol. Hypertens.19: 489-492, 2010).

Metabolic acidosis, regardless of etiology, lowers extracellular fluidbicarbonate and, thus, decreases extracellular pH. The relationshipbetween serum pH and serum bicarbonate is described by theHenderson-Hasselbalch equation

pH=pK′+log [HCO3-]/[(0.03×Paco2)]

where 0.03 is the physical solubility coefficient for CO₂, [HCO₃ ⁻] andPaCO₂ are the concentrations of bicarbonate and the partial pressure ofcarbon dioxide, respectively.

There are several laboratory tests that can be used to define metabolicacidosis. The tests fundamentally measure either bicarbonate (HCO₃ ⁻) orproton (H⁺) concentration in various biological samples, includingvenous or arterial blood.

The most useful measurements for the determination of acidosis rely on ameasurement of the venous plasma bicarbonate (or total carbon dioxide[tCO₂]), serum electrolytes Cl⁻, K⁺, and Na⁺, and a determination of theanion gap. In the clinical laboratory, measurement of venous plasma orserum electrolytes includes an estimation of the tCO2. This measurementreflects the sum of circulating CO₂ [i.e., the total CO₂ represented bybicarbonate (HCO₃ ⁻), carbonic acid, (H₂CO₃) and dissolved CO₂(0.03×Pco₂)]. tCO2 can also be related to HCO₃ ⁻ by using a simplifiedand standardized form of the Henderson-Hasselbalch equation: tCO2=HCO₃ ⁻+0.03 PCO₂, where PCO₂ is the measured partial pressure of CO₂. SinceHCO₃ ⁻ concentration is greater than 90% of the tCO2, and there aresmall amounts of H₂CO₃, then venous tCO2 is often used as a reasonableapproximation of the venous HCO₃ ⁻ concentration in the blood.Especially during chronic kidney disease, an abnormal plasma HCO₃ ⁻value <24-26 mEq/L generally indicates metabolic acidosis.

Changes in serum Cl⁻ concentration can provide additional insights intopossible acid-base disorders, particularly when they aredisproportionate to changes in serum Na⁺ concentration. When thisoccurs, the changes in serum Cl⁻ concentration are typically associatedwith reciprocal changes in serum bicarbonate. Thus, in metabolicacidosis with normal anion gap, serum Cl⁻ increases >105 mEq/L as serumbicarbonate decreases <24-26 mEq/L.

Calculation of the anion gap [defined as the serum Na⁺—(Cl⁻+HCO₃ ⁻)] isan important aspect of the diagnosis of metabolic acidosis. Metabolicacidosis may be present with a normal or an elevated anion gap. However,an elevated anion gap commonly signifies the presence of metabolicacidosis, regardless of the change in serum HCO₃ ⁻. An anion gap greaterthan 20 mEq/L (normal anion gap is 8 to 12 mEq/L) is a typical featureof metabolic acidosis.

Arterial blood gases are used to identify the type of an acid-basedisorder and to determine if there are mixed disturbances. In general,the result of arterial blood gas measures should be coordinated withhistory, physical exam and the routine laboratory data listed above. Anarterial blood gas measures the arterial carbon dioxide tension(P_(a)CO₂), acidity (pH), and the oxygen tension (P_(a)O₂). The HCO₃ ⁻concentration is calculated from the pH and the Paco₂. Hallmarks ofmetabolic acidosis are a pH<7.35, P_(a)CO₂<35 mm Hg and HCO₃ ⁻ <22mEq/L. The value of P_(a)O₂ (normal 80-95 mmHg) is not used in makingthe diagnosis of metabolic acidosis but may be helpful in determiningthe cause. Acid-base disturbance are first classified as respiratory ormetabolic. Respiratory disturbances are those caused by abnormalpulmonary elimination of CO₂, producing an excess (acidosis) or deficit(alkalosis) of CO₂ (carbon dioxide) in the extracellular fluid. Inrespiratory acid-base disorders, changes in serum bicarbonate (HCO₃ ⁻)are initially a direct consequence of the change in Pco₂ with a greaterincrease in Pco₂ resulting in an increase in HCO₃ ⁻. (Adrogue H J,Madias N E, 2003, Respiratory acidosis, respiratory alkalosis, and mixeddisorders, in Johnson R J, Feehally J (eds): Comprehensive ClinicalNephrology. London, CV Mosby, pp. 167-182). Metabolic disturbances arethose caused by excessive intake of, or metabolic production or lossesof, nonvolatile acids or bases in the extracellular fluid. These changesare reflected by changes in the concentration of bicarbonate anion (HCO₃⁻) in the blood; adaptation in this case involves both buffering(immediate), respiratory (hours to days) and renal (days) mechanisms.(DuBose T D, MacDonald G A: renal tubular acidosis, 2002, in DuBose T D,Hamm L L (eds): Acid-base and electrolyte disorders: A companion toBrenners and Rector's the Kidney, Philadelphia, WB Saunders, pp.189-206).

The overall hydrogen ion concentration in the blood is defined by theratio of two quantities, the serum HCO₃ ⁻ content (regulated by thekidneys) and the P_(CO2) content (regulated by the lungs) and isexpressed as follows:

[H⁺]∝(P_(CO2)/[HCO₃ ⁻])

The consequence of an increase in the overall hydrogen ion concentrationis a decline in the major extracellular buffer, bicarbonate. Normalblood pH is between 7.38 and 7.42, corresponding to a hydrogen ion (H⁺)concentration of 42 to 38 nmol/L (Goldberg M: Approach to Acid-BaseDisorders. 2005. In Greenberg A, Cheung A K (eds) Primer on KidneyDiseases, National Kidney Foundation, Philadelphia, Elsevier-Saunders,pp. 104-109.). Bicarbonate (HCO₃ ⁻) is an anion that acts to bufferagainst pH disturbances in the body, and normal levels of plasmabicarbonate range from 22-26 mEq/L (Szerlip H M: Metabolic Acidosis,2005, in Greenberg A, Cheung A K (eds) Primer on Kidney Diseases,National Kidney Foundation, Philadelphia, Elsevier-Saunders, pp.74-89.). Acidosis is the process which causes a reduction in blood pH(acidemia) and reflects the accumulation of hydrogen ion (H+) and itsconsequent buffering by bicarbonate ion (HCO₃) resulting in a decreasein serum bicarbonate. Metabolic acidosis can be represented as follows:

(Clinical practice guidelines for nutrition in chronic renal failure.K/DOQI, National Kidney Foundation. Am. J. Kidney Dis. 2000; 35:S1-140).Using this balance equation, the loss of one HCO₃ ⁻ is equivalent to theaddition of one H⁺ and conversely, the gain of one HCO₃ ⁻ is equivalentto the loss of one H⁺. Thus, changes in blood pH, particularly increasesin H⁺ (lower pH, acidosis) can be corrected by increasing serum HCO₃ ⁻or, equivalently, by decreasing serum H⁺.

In order to maintain extracellular pH within the normal range, the dailyproduction of acid must be excreted from the body. Acid production inthe body results from the metabolism of dietary carbohydrates, fats andamino acids. Complete oxidation of these metabolic substrates produceswater and CO₂. The carbon dioxide generated by this oxidation (˜20,000mmol/day) is efficiently exhaled by the lungs, and represents thevolatile acid component of acid-base balance.

In contrast, nonvolatile acids (˜50-100 mEq/day) are produced by themetabolism of sulfate- and phosphate-containing amino acids and nucleicacids. Additional nonvolatile acids (lactic acid, butyric acid, aceticacid, other organic acids) arise from the incomplete oxidation of fatsand carbohydrates, and from carbohydrate metabolism in the colon, wherebacteria residing in the colon lumen convert the substrates into smallorganic acids that are then absorbed into the bloodstream. The impact ofshort chain fatty acids on acidosis is somewhat minimized by anabolism,for example into long-chain fatty acids, or catabolism to water and CO₂.

The kidneys maintain pH balance in the blood through two mechanisms:reclaiming filtered HCO₃ ⁻ to prevent overall bicarbonate depletion andthe elimination of nonvolatile acids in the urine. Both mechanisms arenecessary to prevent bicarbonate depletion and acidosis.

In the first mechanism, the kidneys reclaim HCO₃ ⁻ that is filtered bythe glomerulus. This reclamation occurs in the proximal tubule andaccounts for ˜4500 mEq/day of reclaimed HCO₃ ⁻. This mechanism preventsHCO₃ from being lost in the urine, thus preventing metabolic acidosis.In the second mechanism, the kidneys eliminate enough H⁺ to equal thedaily nonvolatile acid production through metabolism and oxidation ofprotein, fats and carbohydrates. Elimination of this acid load isaccomplished by two distinct routes in the kidney, comprising activesecretion of H⁺ ion and ammoniagenesis. The net result of these twointerconnected processes is the elimination of the 50-100 mEq/day ofnonvolatile acid generated by normal metabolism.

Thus, normal renal function is needed to maintain acid-base balance.During chronic kidney disease, filtration and reclamation of HCO₃ ⁻ isimpaired as is generation and secretion of ammonia. These deficitsrapidly lead to chronic metabolic acidosis which is, itself, a potentantecedent to end-stage renal disease. With continued acid productionfrom metabolism, a reduction in acid elimination will disturb theH⁺/HCO₃ ⁻ balance such that blood pH falls below the normal value ofpH=7.38-7.42.

Treatment of metabolic acidosis by alkali therapy is usually indicatedto raise and maintain the plasma pH to greater than 7.20. Sodiumbicarbonate (NaHCO₃) is the agent most commonly used to correctmetabolic acidosis. NaHCO₃ can be administered intravenously to raisethe serum HCO₃ ⁻ level adequately to increase the pH to greater than7.20. Further correction depends on the individual situation and may notbe indicated if the underlying process is treatable or the patient isasymptomatic. This is especially true in certain forms of metabolicacidosis. For example, in high-anion gap (AG) acidosis secondary toaccumulation of organic acids, lactic acid, and ketones, the cognateanions are eventually metabolized to HCO₃ ⁻. When the underlyingdisorder is treated, the serum pH corrects; thus, caution should beexercised in these patients when providing alkali to raise the pH muchhigher than 7.20, to prevent an increase in bicarbonate above the normalrange (>26 mEq/L).

Citrate is an appropriate alkali therapy to be given orally or IV,either as the potassium or sodium salt, as it is metabolized by theliver and results in the formation of three moles of bicarbonate foreach mole of citrate. Potassium citrate administered IV should be usedcautiously in the presence of renal impairment and closely monitored toavoid hyperkalemia.

Intravenous sodium bicarbonate (NaHCO₃) solution can be administered ifthe metabolic acidosis is severe or if correction is unlikely to occurwithout exogenous alkali administration. Oral alkali administration isthe preferred route of therapy in persons with chronic metabolicacidosis. The most common alkali forms for oral therapy include NaHCO₃tablets where 1 g of NaHCO₃ is equal to 11.9 mEq of HCO₃ ⁻. However, theoral form of NaHCO₃ is not approved for medical use and the packageinsert of the intravenous sodium bicarbonate solution includes thefollowing contraindications, warnings and precautions (Hospira label forNDC 0409-3486-16):

-   -   Contraindications: Sodium Bicarbonate Injection, USP is        contraindicated in patients who are losing chloride by vomiting        or from continuous gastrointestinal suction, and in patients        receiving diuretics known to produce a hypochloremic alkalosis.    -   Warnings: Solutions containing sodium ions should be used with        great care, if at all, in patients with congestive heart        failure, severe renal insufficiency and in clinical states in        which there exists edema with sodium retention. In patients with        diminished renal function, administration of solutions        containing sodium ions may result in sodium retention. The        intravenous administration of these solutions can cause fluid        and/or solute overloading resulting in dilution of serum        electrolyte concentrations, overhydration, congested states or        pulmonary edema.    -   Precautions: [ . . . ] The potentially large loads of sodium        given with bicarbonate require that caution be exercise in the        use of sodium bicarbonate in patients with congestive heart        failure or other edematous or sodium-retaining states, as well        as in patients with oliguria or anuria.

Acid-base disorders are common in chronic kidney disease and heartfailure patients. Chronic kidney disease (CKD) progressively impairsrenal excretion of the approximately 1 mmol/kg body weight of hydrogenions generated in healthy adults (Yaqoob, M M. 2010, Acidosis andprogression of chronic kidney disease, Curr. Opin. Nephrol. Hyperten.19:489-492.). Metabolic acidosis, resulting from the accumulation ofacid (H⁺) or depletion of base (HCO₃ ⁻) in the body, is a commoncomplication of patients with CKD, particularly when the glomerularfiltration rate (GFR, a measure of renal function) falls below 30ml/min/1.73 m². Metabolic acidosis has profound long term effects onprotein and muscle metabolism, bone turnover and the development ofrenal osteodystrophy. In addition, metabolic acidosis influences avariety of paracrine and endocrine functions, again with long termconsequences such as increased inflammatory mediators, reduced leptin,insulin resistance, and increased corticosteroid and parathyroid hormoneproduction (Mitch W E, 1997, Influence of metabolic acidosis onnutrition, Am. J. Kidney Dis. 29:46-48.). The net effect of sustainedmetabolic acidosis in the CKD patient is loss of bone and muscle mass, anegative nitrogen balance, and the acceleration of chronic renal failuredue to hormonal and cellular abnormalities (De Brito-Ashurst I,Varagunam M, Raftery M J, et al, 2009, Bicarbonate supplementation slowsprogression of CKD and improves nutritional status, J. Am. Soc. Nephrol.20: 2075-2084). Conversely, the potential concerns with alkali therapyin CKD patients include expansion of extracellular fluid volumeassociated with sodium ingestion, resulting in the development oraggravation of hypertension, facilitation of vascular calcification, andthe decompensation of existing heart failure. CKD patients of moderatedegree (GFR at 20-25% of normal) first develop hyperchloremic acidosiswith a normal anion gap due to the inability to reclaim filteredbicarbonate and excrete proton and ammonium cations. As they progresstoward the advanced stages of CKD the anion gap increases, reflective ofthe continuing degradation of the kidney's ability to excrete the anionsthat were associated with the unexcreted protons. Serum bicarbonate inthese patients rarely goes below 15 mmol/L with a maximum elevated aniongap of approximately 20 mmol/L. The non-metabolizable anions thataccumulate in CKD are buffered by alkaline salts from bone (Lemann J Jr,Bushinsky D A, Hamm L L Bone buffering of acid and base in humans. Am.J. Physiol Renal Physiol. 2003 November, 285(5):F811-32).

The majority of patients with chronic kidney disease have underlyingdiabetes (diabetic nephropathy) and hypertension, leading todeterioration of renal function. In almost all patients withhypertension a high sodium intake will worsen the hypertension.Accordingly, kidney, heart failure, diabetes and hypertensive guidelinesstrictly limit sodium intake in these patients to less than 1.5 g or 65mEq per day (HFSA 2010 guidelines, Lindenfeld 2010, J Cardiac FailureV16 No 6 P475). Chronic anti-hypertensive therapies often induce sodiumexcretion (diuretics) or modify the kidney's ability to excrete sodiumand water (such as, for example, Renin Angiotensin Aldosterone Systeminhibiting “RAASi” drugs). However, as kidney function deteriorates,diuretics become less effective due to an inability of the tubule torespond. The RAASi drugs induce life-threatening hyperkalemia as theyinhibit renal potassium excretion. Given the additional sodium load,chronically treating metabolic acidosis patients with amounts ofsodium-containing base that often exceed the total daily recommendedsodium intake is not a reasonable practice. As a consequence, oralsodium bicarbonate is not commonly prescribed chronically in thesediabetic nephropathy patients. Potassium bicarbonate is also notacceptable as patients with CKD are unable to readily excrete potassium,leading to severe hyperkalemia.

Despite these shortcomings, the role of oral sodium bicarbonate has beenstudied in the small subpopulation of non-hypertensive CKD patients. Aspart of the Kidney Research National Dialogue, alkali therapy wasidentified as having the potential to slow the progression of CKD, aswell as to correct metabolic acidosis. The annual age-related decline inglomerular filtration rate (GFR) after the age of 40 is 0.75-1.0ml/min/1.73 m² in normal individuals. In CKD patients with fastprogression, a steeper decline of >4 ml/min/1.73 m² annually can beseen.

In one outcome study, De Brito-Ashurst et al showed that bicarbonatesupplementation preserves renal function in CKD (De Brito-Ashurst I,Varagunam M, Raftery M J, et al, 2009, Bicarbonate supplementation slowsprogression of CKD and improves nutritional status, J. Am. Soc. Nephrol.20: 2075-2084). The study randomly assigned 134 adult patients with CKD(creatinine clearance [CrCl] 15 to 30 ml/min per 1.73 m²) and serumbicarbonate 16 to 20 mmol/L to either supplementation with oral sodiumbicarbonate or standard of care for 2 years. The average dose ofbicarbonate in this study was 1.82 g/day, which provides 22 mEq ofbicarbonate per day. The primary end points were rate of CrCl decline,the proportion of patients with rapid decline of CrCl (>3 ml/min per1.73 m²/yr), and end-stage renal disease (“ESRD”) (CrCl <10 ml/min).Compared with the control group, decline in CrCl was slower withbicarbonate supplementation (decrease of 1.88 ml/min per 1.73 m² forpatients receiving bicarbonate versus a decrease of 5.93 ml/min per 1.73m² for control group; P<0.0001). Patients supplemented with bicarbonatewere significantly less likely to experience rapid progression (9%versus 45%; relative risk 0.15; 95% confidence interval 0.06 to 0.40; P<0.0001). Similarly, fewer patients supplemented with bicarbonatedeveloped ESRD (6.5% versus 33%; relative risk 0.13; 95% confidenceinterval 0.04 to 0.40; P<0.001).

Hyperphosphatemia is a common co-morbidity in patients with CKD,particularly in those with advanced or end-stage renal disease.Sevelamer hydrochloride is a commonly used ion-exchange resin thatreduces serum phosphate concentration. However, reported drawbacks ofthis agent include metabolic acidosis apparently due to the netabsorption of HCl in the process of binding phosphate in the smallintestine. Several studies in patients with CKD and hyperphosphatemiawho received hemodialysis or peritoneal dialysis found decreases inserum bicarbonate concentrations with the use of sevelamer hydrochloride(Brezina, 2004 Kidney Int. V66 S90 (2004) S39-S45; Fan, 2009 NephrolDial Transplant (2009) 24:3794).

Among the various aspects of the present invention, therefore, may benoted compositions for and methods of treating an animal, including ahuman, and methods of preparing such compositions. The compositionscomprise crosslinked amine polymers and may be used, for example, totreat diseases or other metabolic conditions in which removal of protonsand/or chloride ions from the gastrointestinal tract would providephysiological benefits. For example, the polymers described herein maybe used to regulate acid-base related diseases in an animal, including ahuman. In one such embodiment, the polymers described herein may be usedto normalize serum bicarbonate concentrations and the blood pH in ananimal, including a human. By way of further example, the polymersdescribed herein may be used in the treatment of acidosis. There areseveral distinct physiologic conditions that describe this imbalance,each of which can be treated by a polymer that binds and removes HCl.

Metabolic acidosis resulting from a net gain of acid includes processesthat increase endogenous hydrogen ion production, such as ketoacidosis,L-lactic acidosis, D-lactic acidosis and salicylate intoxication.Metabolism of ingested toxins such as methanol, ethylene glycol andparaldehyde can also increase hydrogen ion concentration. Decreasedrenal excretion of hydrogen ions as in uremic acidosis and distal (typeI) renal tubular acidosis is another cause of net gain of acid in thebody resulting in metabolic acidosis. Metabolic acidosis resulting froma loss of bicarbonate is a hallmark of proximal (type II) renal tubularacidosis. In addition, gastrointestinal loss of bicarbonate in acute orchronic diarrhea also results in metabolic acidosis. Primary orsecondary hypoaldosteronism are common disorders causing hyperkalemiaand metabolic acidosis and underlie the classification of type IV renaltubular acidosis. Hyporeninemic hypoaldosteronism is the most frequentlyencountered variety of this disorder.

Another way of describing metabolic acidosis is in terms of the aniongap. Causes of high anion gap acidosis include diabetic ketoacidosis,L-lactic acidosis, D-lactic acidosis, alcoholic ketoacidosis, starvationketoacidosis, uremic acidosis associated with advanced renal failure(CKD Stages 4-5), salicylate intoxication, and selected toxin exposuredue to ingestion including methanol, ethylene, propylene glycol andparaldehyde. Causes of normal anion gap acidosis include early stagerenal failure (CKD Stages 1-3), gastrointestinal loss of bicarbonate dueto acute or chronic diarrhea, distal (type I) renal tubular acidosis,proximal (type II) renal tubular acidosis, type IV renal tubularacidosis, dilutional acidosis associated with large volume intravenousfluid administration, and treatment of diabetic ketoacidosis resultingfrom ketones lost in the urine.

With regard to lactic acidosis, hypoxic lactic acidosis results from animbalance between oxygen balance and oxygen supply and is associatedwith tissue ischemia, seizure, extreme exercise, shock, cardiac arrest,low cardiac output and congestive heart failure, severe anemia, severehypoxemia and carbon monoxide poisoning, vitamin deficiency and sepsis.In other types of lactic acidosis, oxygen delivery is normal butoxidative phosphorylation is impaired, often the result of cellularmitochondrial defects. This is commonly seen in inborn errors ofmetabolism or from the ingestion of drugs or toxins. Alternate sugarsused for tube feedings or as irrigants during surgery (e.g., fructose,sorbitol) can also result in metabolism that triggers lactic acidosis.

There are three main classifications of renal tubular acidosis, eachwith distinctive etiologies with several sub-types. Distal (type I)renal tubular acidosis can be caused by hereditary and genomic changes,particularly mutation in the HCO₃ ⁻/Cl⁻ exchanger (AE1) or H⁺/ATPase.Examples of acquired distal (type I) renal tubular acidosis includehyperparathyroidism, Sjogren's syndrome, medullary sponge kidney,cryoglobulinemia, systemic lupus erythematosus, kidney transplantrejection, chronic tubulointerstitial disease and exposure to variousdrugs including amphotericin B, lithium, ifosfamide, foscarnet, tolueneand vanadium. A special classification of distal (type IV) renal tubularacidosis with hyperkalemia is found in lupus nephritis, obstructivenephropathy, sickle cell anemia, and voltage defects. Hereditaryexamples include pseudohypoaldosteronism type I andpseudohypoaldosteronism type II (Gordon's disease) and exposure tocertain drugs (amiloride, triamterene, trimethoprim, and pentamidine)can also result in distal (type IV) renal tubular acidosis withhyperkalemia. Proximal (type II) renal tubular acidosis can be caused byhereditary or acquired causes. Hereditary causes include Wilson'sdisease and Lowe's syndrome. Acquired causes include cystinosis,galactosemia, multiple myeloma, light chain disease, amyloidosis,vitamin D deficiency, lead and mercury ingestion, and exposure tocertain drugs including ifosfamide, cidofovir, aminoglycosides, andacetazolamide. Isolated defects in bicarbonate reabsorption can be acause of proximal (type II) renal tubular acidosis; example of suchdefects include exposure to carbonic anhydrase inhibitors,acetazolamide, topiramate, sulfamylon and carbonic anhydrase deficiency.Combined proximal and distal renal tubular acidosis (type III) isuncommon and results from defects in both proximal bicarbonatereabsorption and distal proton secretion. Mutations in the gene forcystolic carbonic anhydrase can cause the defect, as well as certaindrugs including ifosfamide. Type IV renal tubular acidosis withhyperkalemia is a cause of metabolic acidosis. The main etiology behindthis type of acidosis is aldosterone deficiency; hypoaldosteronismresults from primary adrenal failure, the syndrome of hyporeninemichypoaldosteronism (Type IV RTA) commonly seen in elderly individuals,Addison's disease, and pseudohypoaldosteronism type I due tomineralocorticoid resistance. Chronic interstitial nephritis due toanalgesic nephropathy, chronic pyelonephritis, obstructive nephropathyand sickle cell disease can also create an acidosis with hyperkalemia.Finally, drugs such as amiloride, spironolactone, triamterene,trimethoprim, heparin therapy, NSAIDs, angiotensin receptor blockers andangiotensin-converting enzyme inhibitors can induce metabolic acidosisaccompanied by hyperkalemia.

All of the above causes and etiologies of metabolic acidosis aretreatable with a polymer designed to bind and remove HCl in thegastrointestinal tract.

The method of treatment generally involves administering atherapeutically effective amount of a crosslinked amine polymer havingthe capacity to remove protons and chloride ions from thegastrointestinal tract of an animal, such as a human. In general, suchcrosslinked amine polymers have two or more of the characteristics ofrelatively low swelling, relatively high proton and chloride ionbinding, and/or relatively low binding of interfering anions such asphosphate, citrate, short chain fatty acids and bile acids. In thefollowing examples and embodiments, unless otherwise noted, thecrosslinked amine polymers are used in the free amine form, and in orderto bind anions require protonation of the amines. As such, many of theassays report anion binding, and due to the requisite low degree ofamine quaternization, anion binding is presumed to approximate theamount of proton binding. For example, in one embodiment the crosslinkedamine polymer possesses at least two of the following characteristics:(i) a proton-binding capacity and a chloride binding capacity of atleast about 5 mmol/g in Simulated Gastric Fluid (“SGF”); (ii) a SwellingRatio of less than about 5; (iii) a chloride to phosphate ion bindingratio of at least about 0.35:1, respectively, in Simulated SmallIntestine Inorganic Buffer (“SIB”), (iv) a selectivity for chloride overother anions in Simulated Small Intestine Organic and Inorganic Buffer(“SOB”), (v) a mean particle size of about 80-120 microns, (vi)retention of more than about 50% of the HCl bound when submitted to achloride retention assay (“CRA”, defined below), (vii) no more thanabout 40% of quaternized amine groups before administration to ananimal, including a human, as measured in the quaternized amine assay(“QAA”) in order to ensure proton binding which constitutes the maintherapeutic action of the polymer, (viii) a chloride to interferinganion binding ratio of at least about 0.35:1, respectively, in “SOB”,(ix) a molecular weight per nitrogen of between 50 and 170 daltons,and/or (x) a crosslinker weight percent range of 25 to 90%. For example,in one such embodiment the crosslinked amine polymer possesses twocharacteristics of characteristics “(i)” to “(x)” identified in thisparagraph. By way of further example, in one such embodiment thecrosslinked amine polymer possesses at least three characteristics ofcharacteristics “(i)” to “(x)” identified in this paragraph. By way offurther example, in one such embodiment the crosslinked amine polymerpossesses at least four characteristics of characteristics “(i)” to“(x)” identified in this paragraph. By way of further example, in onesuch embodiment the crosslinked amine polymer possesses at least fivecharacteristics of characteristics “(i)” to “(x)” identified in thisparagraph. By way of further example, in one such embodiment thecrosslinked amine polymer possesses at least six characteristics ofcharacteristics “(i)” to “(x)” identified in this paragraph. By way offurther example, in one such embodiment the crosslinked amine polymerpossesses at least seven characteristics of characteristics “(i)” to“(x)” identified in this paragraph. By way of further example, in onesuch embodiment the crosslinked amine polymer possesses at least eightcharacteristics of characteristics “(i)” to “(x)” identified in thisparagraph.

In one embodiment, the crosslinked amine polymer is administered as apharmaceutical composition comprising the crosslinked amine polymer and,optionally, a pharmaceutically acceptable carrier, diluent or excipient,or combination thereof that do not significantly interfere with theproton and/or chloride binding characteristics of the crosslinked aminepolymer in vivo. Optionally, the pharmaceutical composition may alsocomprise an additional therapeutic agent.

In some embodiments, the pharmaceutical composition comprises acrosslinked amine polymer having (i) a chloride to phosphate ion bindingratio of at least 0.35:1, respectively, in Simulated Small IntestineInorganic Buffer (“SIB”), and (ii) a Swelling Ratio not in excess ofabout 5.

In some embodiments, the pharmaceutical composition comprises acrosslinked amine polymer having (i) a selectivity for chloride overother anions in Simulated Small Intestine Organic and Inorganic Buffer(“SOB”), and (ii) a Swelling Ratio not in excess of about 5.

In some embodiments, the pharmaceutical composition comprises acrosslinked amine polymer having (i) a proton-binding capacity and achloride binding capacity of at least 5 mmol/g in Simulated GastricFluid; and (ii) a Swelling Ratio not in excess of about 2.

In some embodiments, the pharmaceutical composition comprises acrosslinked amine polymer having (i) a proton-binding capacity and achloride binding capacity of at least 5 mmol/g in Simulated GastricFluid; (ii) a Swelling Ratio of less than 5, and (iii) a chloride tophosphate ion binding ratio of at least 0.35:1, respectively, inSimulated Small Intestine Inorganic Buffer (“SIB”).

In some embodiments, the pharmaceutical composition comprises acrosslinked amine polymer having (i) a proton-binding capacity and achloride binding capacity of at least 5 mmol/g in Simulated GastricFluid; (ii) a Swelling Ratio of less than 5, and (iii) a selectivity forchloride over other anions in Simulated Small Intestine Organic andInorganic Buffer (“SOB”).

In some embodiments, the pharmaceutical composition comprises acrosslinked amine polymer having i) a chloride binding capacity of >2mmol/g in Simulated Organic/Inorganic Buffer (SOB) and ii) >50%retention of the bound chloride when assessed in the chloride retentionassay (CRA).

In some embodiments, the pharmaceutical composition comprises acrosslinked amine polymer having i) a chloride binding capacity of >5mmol/g in simulated gastric fluid (SGF) and ii) has no more than 40% ofquaternized amine groups as measured in the quaternized amine assay(QAA).

In some embodiments, the pharmaceutical composition comprises acrosslinked amine polymer comprising the residue of an aminecorresponding to Formula 1

wherein R₁, R₂ and R₃ are independently hydrogen, hydrocarbyl, orsubstituted hydrocarbyl provided, however, at least one of R₁, R₂ and R₃is other than hydrogen, and the crosslinked amine polymer has (i) anequilibrium proton binding capacity of at least 5 mmol/g and a chlorideion binding capacity of at least 5 mmol/g in an aqueous simulatedgastric fluid buffer (“SGF”) containing 35 mM NaCl and 63 mM HCl at pH1.2 and 37° C., and (ii) an equilibrium swelling ratio in deionizedwater of about 2 or less.

In some embodiments, the pharmaceutical composition comprises acrosslinked amine polymer comprising the residue of an aminecorresponding to Formula 1

wherein R₁, R₂ and R₃ are independently hydrogen, hydrocarbyl,substituted hydrocarbyl provided, however, at least one of R₁, R₂ and R₃is other than hydrogen, the crosslinked amine polymer has an equilibriumswelling ratio in deionized water of about 5 or less, and thecrosslinked amine polymer binds a molar ratio of chloride ions tointerfering ions of at least 0.35:1, respectively, in an interfering ionbuffer at 37° C. wherein (i) the interfering ions are phosphate ions andthe interfering ion buffer is a buffered solution at pH 5.5 of 36 mMchloride and 20 mM phosphate or (ii) the interfering ions are phosphate,citrate and taurocholate ions and the interfering ion buffer is abuffered solution at pH 6.2 including 36 mM chloride, 7 mM phosphate,1.5 mM citrate, and 5 mM taurocholate. Statted differently, in theembodiment in which the interfering ion buffer is a buffered solution atpH 5.5 of 36 mM chloride and 20 mM phosphate, the ratio of chloride tointerfering ions is a ratio of chloride to phosphate ions and in theembodiment in which the interfering ion buffer is a buffered solution atpH 6.2 including 36 mM chloride, 7 mM phosphate, 1.5 mM citrate, and 5mM taurocholate, the ratio of chloride to interfering ions is a ratio ofchloride ions to the combined (total) amount of phosphate, citrate andtaurocholate ions.

In some embodiments, the crosslinked amine polymer is derived from thepolymerization of an amine corresponding to Formula 2

wherein

m and n are independently non-negative integers;

R₁₀, R₂₀, R₃₀, and R₄₀ are independently hydrogen, hydrocarbyl, orsubstituted hydrocarbyl,

X₁ is

X₂ is hydrocarbyl or substituted hydrocarbyl;

each X₁₁ is independently hydrogen, hydrocarbyl, substitutedhydrocarbyl, hydroxyl, amino, boronic acid, or halo; and

z is a non-negative number.

A further aspect of the present disclosure is a method of crosslinking aproton-binding intermediate with a polyfunctional crosslinker to provideone or more of the characteristics of relatively low swelling,relatively high proton and chloride ion binding, and/or relatively lowinterference from interfering ions. The proton-binding intermediate maybe, for example, an oligomer or polymer containing amine moietiesprepared by (i) substitution polymerization, (ii) additionpolymerization, or (iii) post-polymerization crosslinking of anintermediate.

Other aspects and features will be in part apparent and in part pointedout hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A-1C is a flow chart schematically depicting the mechanism ofaction of the polymer when passing through the gastrointestinal tract ofan individual from oral ingestion/stomach (FIG. 1A), to the upper GItract (FIG. 1B) to the lower GI tract/colon (FIG. 1C).

FIG. 2 is Is a graph of the relationship between swelling ratios ofpolymers of the current disclosure versus the chloride:phosphate bindingratio in SIB.

ABBREVIATIONS AND DEFINITIONS

The following definitions and methods are provided to better define thepresent invention and to guide those of ordinary skill in the art in thepractice of the present invention. Unless otherwise noted, terms are tobe understood according to conventional usage by those of ordinary skillin the relevant art.

The term “acrylamide” denotes a moiety having the structural formulaH₂C═CH—C(O)NR—*, where * denotes the point of attachment of the moietyto the remainder of the molecule and R is hydrogen, hydrocarbyl, orsubstituted hydrocarbyl.

The term “acrylic” denotes a moiety having the structural formulaH₂C═CH—C(O)O—*, where * denotes the point of attachment of the moiety tothe remainder of the molecule.

The term “alicyclic”, “alicyclo” or “alicyclyl” means a saturatedmonocyclic group of 3 to 8 carbon atoms and includes cyclopentyl,cyclohexyl, cycloheptyl, and the like.

The term “aliphatic” denotes saturated and non-aromatic unsaturatedhydrocarbyl moieties having, for example, one to about twenty carbonatoms or, in specific embodiments, one to about twelve carbon atoms, oneto about ten carbon atoms, one to about eight carbon atoms, or even oneto about four carbon atoms. The aliphatic groups include, for example,alkyl moieties such as methyl, ethyl, n-propyl, isopropyl, n-butyl,isobutyl, sec-butyl, tert-butyl, pentyl, iso-amyl, hexyl and the like,and alkenyl moieties of comparable chain length.

The term “alkanol” denotes an alkyl moiety that has been substitutedwith at least one hydroxyl group. In some embodiments, alkanol groupsare “lower alkanol” groups comprising one to six carbon atoms, one ofwhich is attached to an oxygen atom. In other embodiments, lower alkanolgroups comprise one to three carbon atoms.

The term “alkenyl group” encompasses linear or branched carbon radicalshaving at least one carbon-carbon double bond. The term “alkenyl group”can encompass conjugated and non-conjugated carbon-carbon double bondsor combinations thereof. An alkenyl group, for example and without beinglimited thereto, can encompass two to about twenty carbon atoms or, in aparticular embodiment, two to about twelve carbon atoms. In certainembodiments, alkenyl groups are “lower alkenyl” groups having two toabout four carbon atoms. Examples of alkenyl groups include, but are notlimited thereto, ethenyl, propenyl, allyl, vinyl, butenyl and4-methylbutenyl. The terms “alkenyl group” and “lower alkenyl group”,encompass groups having “cis” or “trans” orientations, or alternatively,“E” or “Z” orientations.

The term “alkyl group” as used, either alone or within other terms suchas “haloalkyl group,” “aminoalkyl group” and “alkylamino group”,encompasses saturated linear or branched carbon radicals having, forexample, one to about twenty carbon atoms or, in specific embodiments,one to about twelve carbon atoms. In other embodiments, alkyl groups are“lower alkyl” groups having one to about six carbon atoms. Examples ofsuch groups include, but are not limited thereto, methyl, ethyl,n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl,iso-amyl, hexyl and the like. In more specific embodiments, lower alkylgroups have one to four carbon atoms.

The term “alkylamino group” refers to amino groups directly attached tothe remainder of the molecule via the nitrogen atom of the amino groupand wherein the nitrogen atom of the alkylamino group is substituted byone or two alkyl groups. In some embodiments, alkylamino groups are“lower alkylamino” groups having one or two alkyl groups of one to sixcarbon atoms, attached to a nitrogen atom. In other embodiments, loweralkylamino groups have one to three carbon atoms. Suitable “alkylamino”groups may be mono or dialkylamino such as N-methylamino, N-ethylamino,N,N-dimethylamino, N,N-diethylamino, pentamethyleneamine and the like.

The term “allyl” denotes a moiety having the structural formulaH₂C═CH—CH₂—*, where * denotes the point of attachment of the moiety tothe remainder of the molecule and the point of attachment is to aheteroatom or an aromatic moiety.

The term “allylamine” denotes a moiety having the structural formulaH₂C═CH—CH₂N(X₈)(X₉), wherein X₈ and X₉ are independently hydrogen,hydrocarbyl, or substituted hydrocarbyl, or X₈ and X₉ taken togetherform a substituted or unsubstituted alicyclic, aryl, or heterocyclicmoiety, each as defined in connection with such term, typically havingfrom 3 to 8 atoms in the ring.

The term “amine” or “amino” as used alone or as part of another group,represents a group of formula —N(X₈)(X₉), wherein X₈ and X₉ areindependently hydrogen, hydrocarbyl, or substituted hydrocarbyl,heteroaryl, or heterocyclo, or X₈ and X₉ taken together form asubstituted or unsubstituted alicyclic, aryl, or heterocyclic moiety,each as defined in connection with such term, typically having from 3 to8 atoms in the ring.

The term “aminoalkyl group” encompasses linear or branched alkyl groupshaving one to about ten carbon atoms, any one of which may besubstituted with one or more amino groups, directly attached to theremainder of the molecule via an atom other than a nitrogen atom of theamine group(s). In some embodiments, the aminoalkyl groups are “loweraminoalkyl” groups having one to six carbon atoms and one or more aminogroups. Examples of such groups include aminomethyl, aminoethyl,aminopropyl, aminobutyl and aminohexyl.

The term “aromatic group” or “aryl group” means an aromatic group havingone or more rings wherein such rings may be attached together in apendent manner or may be fused. In particular embodiments, an aromaticgroup is one, two or three rings. Monocyclic aromatic groups may contain5 to 10 carbon atoms, typically 5 to 7 carbon atoms, and more typically5 to 6 carbon atoms in the ring. Typical polycyclic aromatic groups havetwo or three rings. Polycyclic aromatic groups having two ringstypically have 8 to 12 carbon atoms, preferably 8 to 10 carbon atoms inthe rings. Examples of aromatic groups include, but are not limited to,phenyl, naphthyl, tetrahydronaphthyl, indanyl, biphenyl, phenanthryl,anthryl or acenaphthyl.

The term “bead” is used to describe a crosslinked polymer that issubstantially spherical in shape.

The term “binds” as used herein in connection with a polymer and one ormore ions, that is, a cation (e.g. “proton-binding” polymer) and ananion, is an “ion-binding” polymer and/or when it associates with theion, generally though not necessarily in a non-covalent manner, withsufficient association strength that at least a portion of the ionremains bound under the in vitro or in vivo conditions in which thepolymer is used for sufficient time to effect a removal of the ion fromsolution or from the body.

The term “chloride retention assay” or “CRA” denotes an assay where theretention of chloride and other anions by free amine test polymers, aswell as that of free amine sevelamer and bixalomer control polymers, isevaluated by exposing them to competing anion concentrations typical ofthe colon lumen. The anions released from the polymers and anionsretained by the polymers under these conditions are measured. The firststep in the retention assay is to perform a specific organic/inorganicbuffer assay (SOB screen) as described elsewhere herein. Blank tubesthat contain no polymer are included and processed in an identicalmanner throughout the retention screen. Instead of discarding thepolymer and SOB matrix from the assay tubes, the contents aretransferred to solid phase extraction (SPE) tubes, fitted with 20micrometer pore-size frits. The excess SOB matrix is removed either byapplying negative pressure to the bottom of the SPE tubes, or positivepressure to the tops. The SOB assay tubes are rinsed twice withdeionized water and the contents transferred to the SPE tubes to ensurethat as much of the polymer as possible is recovered. Retention assaymatrix is then added to the SPE tubes. The retention assay matrixcomprises 50 mM 2-(N-morpholino)ethanesulfonic acid (MES), 100 mM sodiumacetate, 5 mM sodium phosphate, 15 mM sulphate, adjusted to pH 6.2. Theconcentrations of potential competing anions reflect typical late-colonlumen concentrations (Wrong, O et al. [1965] Clinical Science 28,357-375). Chloride is omitted since the objective is to measure chlorideretention and bicarbonate is omitted since it is unstable due toconversion to water and CO₂. Retention buffer is added to achieve afinal polymer concentration of 2.5 mg/ml (assuming no loss of polymersince the original weighing into the SOB assay tubes). The SPE tubes arecapped and sealed and incubated at 37° C. for approximately 40 hours. A600 microliter sample is removed, filtered, diluted if necessary, andassayed for anion content as described above for SOB. For each testedpolymer, chloride, citrate and taurocholate released from the polymer inretention matrix are calculated using the following calculation

${{mmol}\mspace{14mu} {of}\mspace{14mu} {ion}\mspace{14mu} {released}\mspace{14mu} g^{- 1}\mspace{14mu} {polymer}} = \frac{\left( {{\lbrack{Ion}\rbrack {ret}} - {\lbrack{Ion}\rbrack \mspace{14mu} {retblank} \times {dilution}\mspace{14mu} {factor}}} \right.}{2.5}$

where [Ion] ret corresponds to the concentration of an ion in theretention matrix at the end of the 48 hour incubation, [Ion] retblankcorresponds to the value of that particular ion in the retention matrixfrom the blank SPE tubes, dilution factor is the dilution factor ifnecessary, and 2.5 is the polymer concentration in mg/ml. The excessretention matrix is removed either by applying negative pressure to thebottom of the SPE tubes, or positive pressure to the tops. The SPEcolumns are washed briefly with 10 ml of deionized water and excesswater is removed. Ions that remain bound to the polymers are eluted byadding 0.2M NaOH to the SPE tubes to achieve a final polymerconcentration of 2.5 mg/ml (assuming no loss of polymer since theoriginal weighing into the SOB assay tubes) and incubating for 16-20hours at 37° C. A 600 microliter sample is removed, filtered, diluted ifnecessary, and assayed for anion content as described above for SOB. Foreach tested polymer, chloride, phosphate, citrate and taurocholatereleased from the polymer in retention matrix is calculated using thefollowing calculation

${{mmol}\mspace{14mu} {of}\mspace{14mu} {ion}\mspace{14mu} {released}\mspace{14mu} g^{- 1}\mspace{14mu} {polymer}} = \frac{\left( {{\lbrack{Ion}\rbrack {elu}} - {\lbrack{Ion}\rbrack \mspace{14mu} {elublank} \times {dilution}\mspace{14mu} {factor}}} \right.}{2.5}$

where [Ion] elu corresponds to the concentration of an ion in the 0.2MNaOH elution matrix at the end of the 16-20 hours incubation, [Ion]elublank corresponds to the value of that particular ion in the elutionmatrix from the blank SPE tubes, dilution factor is the dilution factorif necessary, and 2.5 is the polymer concentration in mg/ml.

The term “crosslink density” denotes the average number of connectionsof the amine containing repeat unit to the rest of the polymer. Thenumber of connections can be 2, 3, 4 and higher. Repeat units in linear,non crosslinked polymers are incorporated via 2 connections. In order toform an insoluble gel, the number of connections should be greater than2. Low crosslinking density materials such as sevelamer have on averageabout 2.1 connections between repeat units. More crosslinked systemssuch as bixalomer have on average about 4.6 connections between theamine-containing repeat units. “Crosslinking density” represents asemi-quantitative measure based on the ratios of the starting materialsused. Limitations include the fact that it does not account fordifferent crosslinking and polymerization methods. For example, smallmolecule amine systems require higher amounts of crosslinker as thecrosslinker also serves as the monomer to form the polymer backbonewhereas for radical polymerizations the polymer chain is formedindependent from the crosslinking reaction. This can lead to inherentlyhigher crosslinking densities under this definition for the substitutionpolymerization/small molecule amines as compared to radicalpolymerization crosslinked materials.

The term “crosslinker” as used, either alone or within other terms,encompasses hydrocarbyl or substituted hydrocarbyl, linear or branchedmolecules capable of reacting with any of the described monomers, or theinfinite polymer network, as described in Formula 1, more than one time.The reactive group in the crosslinker can include, but is not limited toalkyl halide, epoxide, phosgene, anhydride, carbamate, carbonate,isocyanate, thioisocyanate, esters, activated esters, carboxylic acidsand derivatives, sulfonates and derivatives, acyl halides, aziridines,alpha, beta-unsaturated carbonyls, ketones, aldehydes, pentafluoroarylgroups, vinyl, allyl, acrylate, methacrylate, acrylamide,methacrylamide, styrenic, acrylonitriles and combinations thereof. Inone exemplary embodiment, the crosslinker's reactive group will includealkyl halide, epoxide, anhydrides, isocyanates, allyl, vinyl,acrylamide, and combinations thereof. In one such embodiment, thecrosslinker's reactive group will be alkyl halide, epoxide, or allyl.

The term “diallylamine” denotes an amino moiety having two allyl groups.

The term “ethereal” denotes a moiety having an oxygen bound to twoseparate carbon atoms as depicted the structural formula*—H_(x)C—O—CH_(x)—*, where * denotes the point of attachment to theremainder of the moiety and x independently equals 0, 1, 2, or 3.

The term “gel” is used to describe a crosslinked polymer that has anirregular shape.

The term “halo” means halogens such as fluorine, chlorine, bromine oriodine atoms.

The term “haloalkyl group” encompasses groups wherein any one or more ofthe alkyl carbon atoms is substituted with halo as defined above.Specifically encompassed are monohaloalkyl, dihaloalkyl andpolyhaloalkyl groups including perhaloalkyl. A monohaloalkyl group, forexample, may have either an iodo, bromo, chloro or fluoro atom withinthe group. Dihalo and polyhaloalkyl groups may have two or more of thesame halo atoms or a combination of different halo groups. “Lowerhaloalkyl group” encompasses groups having 1-6 carbon atoms. In someembodiments, lower haloalkyl groups have one to three carbon atoms.Examples of haloalkyl groups include fluoromethyl, difluoromethyl,trifluoromethyl, chloromethyl, dichloromethyl, trichloromethyl,pentafluoroethyl, heptafluoropropyl, difluorochloromethyl,dichlorofluoromethyl, difluoroethyl, difluoropropyl, dichloroethyl anddichloropropyl.

The term “heteroaliphatic” describes a chain of 1 to 25 carbon atoms,typically 1 to 12 carbon atoms, more typically 1 to 10 carbon atoms, andmost typically 1 to 8 carbon atoms, and in some embodiments 1 to 4carbon atoms that can be saturated or unsaturated (but not aromatic),containing one or more heteroatoms, such as halogen, oxygen, nitrogen,sulfur, phosphorus, or boron. A heteroatom atom may be a part of apendant (or side) group attached to a chain of atoms (e.g., —CH(OH)——CH(NH₂)— where the carbon atom is a member of a chain of atoms) or itmay be one of the chain atoms (e.g., —ROR— or —RNHR— where each R isaliphatic). Heteroaliphatic encompasses heteroalkyl and heterocyclo butdoes not encompass heteroaryl.

The term “heteroalkyl” describes a fully saturated heteroaliphaticmoiety.

The term “heteroaryl” means a monocyclic or bicyclic aromatic radical of5 to 10 ring atoms, unless otherwise stated, where one or more, (in oneembodiment, one, two, or three), ring atoms are heteroatom selected fromN, O, or S, the remaining ring atoms being carbon. Representativeexamples include, but are not limited to, pyrrolyl, thienyl, thiazolyl,imidazolyl, furanyl, indolyl, isoindolyl, oxazolyl, isoxazolyl,benzothiazolyl, benzoxazolyl, quinolinyl, isoquinolinyl, pyridinyl,pyrimidinyl, pyrazinyl, pyridazinyl, triazolyl, tetrazolyl, and thelike. As defined herein, the terms “heteroaryl” and “aryl” are mutuallyexclusive. “Heteroarylene” means a divalent heteroaryl radical.

The term “heteroatom” means an atom other than carbon and hydrogen.Typically, but not exclusively, heteroatoms are selected from the groupconsisting of halogen, sulfur, phosphorous, nitrogen, boron and oxygenatoms. Groups containing more than one heteroatom may contain differentheteroatoms.

The term “heterocyclo,” “heterocyclic,” or heterocyclyl” means asaturated or unsaturated group of 4 to 8 ring atoms in which one or tworing atoms are heteroatom such as N, O, B, P and S(O)_(n), where n is aninteger from 0 to 2, the remaining ring atoms being carbon.Additionally, one or two ring carbon atoms in the heterocyclyl ring canoptionally be replaced by a —C(O)— group. More specifically the termheterocyclyl includes, but is not limited to, pyrrolidino, piperidino,homopiperidino, 2-oxopyrrolidinyl, 2-oxopiperidinyl, morpholino,piperazino, tetrahydro-pyranyl, thiomorpholino, and the like. When theheterocyclyl ring is unsaturated it can contain one or two ring doublebonds provided that the ring is not aromatic. When the heterocyclylgroup contains at least one nitrogen atom, it is also referred to hereinas heterocycloamino and is a subset of the heterocyclyl group.

The term “hydrocarbon group” or “hydrocarbyl group” means a chain of 1to 25 carbon atoms, typically 1 to 12 carbon atoms, more typically 1 to10 carbon atoms, and most typically 1 to 8 carbon atoms. Hydrocarbongroups may have a linear or branched chain structure. Typicalhydrocarbon groups have one or two branches, typically one branch.Typically, hydrocarbon groups are saturated. Unsaturated hydrocarbongroups may have one or more double bonds, one or more triple bonds, orcombinations thereof. Typical unsaturated hydrocarbon groups have one ortwo double bonds or one triple bond; more typically unsaturatedhydrocarbon groups have one double bond.

“Initiator” is a term used to describe a reagent that initiates apolymerization.

The term “molecular weight per nitrogen” or “MW/N” represents thecalculated molecular weight in the polymer per nitrogen atom. Itrepresents the average molecular weight to present one amine functionwithin the crosslinked polymer. It is calculated by dividing the mass ofa polymer sample by the moles of nitrogen present in the sample. “MW/N”is the inverse of theoretical capacity, and the calculations are basedupon the feed ratio, assuming full reaction of crosslinker and monomer.The lower the molecular weight per nitrogen the higher the theoreticalcapacity of the crosslinked polymer.

“Optional” or “optionally” means that the subsequently described eventor circumstance may but need not occur, and that the descriptionincludes instances where the event or circumstance occurs and instancesin which it does not. For example, “heterocyclyl group optionallysubstituted with an alkyl group” means that the alkyl may but need notbe present, and the description includes embodiments in which theheterocyclyl group is substituted with an alkyl group and embodiments inwhich the heterocyclyl group is not substituted with alkyl.

“Pharmaceutically acceptable” as used in connection with a carrier,diluent or excipient means a carrier, diluent or an excipient,respectively, that is useful in preparing a pharmaceutical compositionthat is generally safe, non-toxic and neither biologically nor otherwiseundesirable for veterinary use and/or human pharmaceutical use.

The term “post polymerization crosslinking” is a term that describes areaction to an already formed bead or gel, where more crosslinking isintroduced to the already formed bead or gel to create a bead or gelthat has an increased amount of crosslinking.

The term “post polymerization modification” is a term that describes amodification to an already formed bead or gel, where a reaction or atreatment introduces an additional functionality. This functionality canbe linked either covalently or non-covalently to the already formedbead.

The term “quaternized amine assay” (“QAA”) describes a method toestimate the amount of quaternary amines present in a given crosslinkedpolymer sample. This assay measures chloride binding of a crosslinkedamine polymer at a pH of 11.5. At this pH, primary, secondary andtertiary amines are not substantially protonated and do notsubstantially contribute to chloride binding. Therefore, any bindingobserved under these conditions can be attributed to the presence ofpermanently charged quaternary amines. The test solution used for QAAassay is 100 mM sodium chloride at a pH of 11.5. The concentration ofchloride ions is similar to that in the SGF assay which is used toassess total binding capacity of crosslinked amine polymers. Quaternaryamine content as a percentage of total amines present is calculated asfollows:

${\% \mspace{14mu} {Quaternary}\mspace{14mu} {amines}} = {\frac{{Chloride}\mspace{14mu} {bound}\mspace{11mu} \left( {{mmol}\text{/}g} \right)\mspace{14mu} {in}\mspace{14mu} {QAA}}{{Chloride}\mspace{14mu} {bound}\mspace{11mu} \left( {{mmol}\text{/}g} \right)\mspace{14mu} {in}\mspace{14mu} {SGF}} \times 100}$

To perform the QAA assay, the free-amine polymer being tested isprepared at a concentration of 2.5 mg/ml (e.g. 25 mg dry mas) in 10 mLof QAA buffer. The mixture is incubated at 37° C. for ˜16 hours withagitation on a rotisserie mixer. After incubation and mixing, 600microliters of supernatant is removed and filtered using a 800microliter, 0.45 micrometer pore size, 96-well poly propylene filterplate. With the samples arrayed in the filter plate and the collectionplate fitted on the bottom, the unit is centrifuged at 1000×g for 1minute to filter the samples. After filtration into the collectionplate, the respective filtrates are diluted appropriately beforemeasuring for chloride content. The IC method (e.g. ICS-2100 IonChromatography, Thermo Fisher Scientific) used for the analysis ofchloride content in the filtrates consists of a 15 mM KOH mobile phase,an injection volume of 5 microliters, with a run time of three minutes,a washing/rinse volume of 1000 microliters, and flow rate of 1.25mL/min. To determine the chloride bound to the polymer, the followingcalculation is completed:

${{Binding}\mspace{14mu} {capacity}\mspace{14mu} {expressed}\mspace{14mu} {as}\mspace{11mu} {mmol}\mspace{14mu} {chloride}\text{/}g\mspace{14mu} {dry}\mspace{14mu} {polymer}} = \frac{\left( {{{Cl}\mspace{14mu} {start}} - {{Cl}\mspace{14mu} {eq}}} \right)}{2.5}$

where Cl start corresponds to the starting concentration of chloride inthe QAA buffer, Cl eq corresponds to the equilibrium value of chloridein the measured filtrates after exposure to the test polymer, and 2.5 isthe polymer concentration in mg/ml.

“Simulated Gastric Fluid” or “SGF” Assay describes a test to determinetotal chloride binding capacity for a test polymer using a definedbuffer that simulates the contents of gastric fluid as follows:Simulated gastric fluid (SGF) consists of 35 mM NaCl, 63 mM HCl, pH 1.2.To perform the assay, the free-amine polymer being tested is prepared ata concentration of 2.5 mg/ml (25 mg dry mass) in 10 mL of SGF buffer.The mixture is incubated at 37° C. overnight for ˜12-16 hours withagitation on a rotisserie mixer. After incubation and mixing, the tubescontaining the polymer are centrifuged for 2 minutes at 500-1000×g topellet the test samples. Approximately 750 microliters of supernatantare removed and filtered using an appropriate filter, for example a 0.45micrometer pore-size syringe filter or an 800 microliter, 1 micrometerpore-size, 96-well, glass filter plate that has been fitted over a96-well 2 mL collection plate. With the latter arrangement multiplesamples tested in SGF buffer can be prepared for analysis, including thestandard controls of free amine sevelamer, free amine bixalomer and acontrol tube containing blank buffer that is processed through all ofthe assay steps. With the samples arrayed in the filter plate and thecollection plate fitted on the bottom, the unit is centrifuged at 1000×gfor 1 minute to filter the samples. In cases of small sample sets, asyringe filter may be used in lieu of the filter plate, to retrieve ˜2-4mL of filtrate into a 15 mL container. After filtration, the respectivefiltrates are diluted 4× with water and the chloride content of thefiltrate is measured via ion chromatography (IC). The IC method (e.g.Dionex ICS-2100, Thermo Scientific) consists of an AS11 column and a 15mM KOH mobile phase, an injection volume of 5 microliters, with a runtime of 3 minutes, a washing/rinse volume of 1000 microliters, and flowrate of 1.25 mL/min. To determine the chloride bound to the polymer, thefollowing calculation is completed:

$\frac{\left( {{{Cl}\mspace{14mu} {start}} - {{Cl}\mspace{14mu} {eq}}} \right) \times 4}{2.5}.$

Binding capacity expressed as mmol chloride/g polymer: where Cl startcorresponds to the starting concentration of chloride in the SGF buffer,Cl eq corresponds to the equilibrium value of chloride in the dilutedmeasured filtrates after exposure to the test polymer, 4 is the dilutionfactor and 2.5 is the polymer concentration in mg/ml.

“Simulated Small Intestine Inorganic Buffer” or “SIB” is a test todetermine the chloride and phosphate binding capacity of free amine testpolymers in a selective specific interfering buffer assay (SIB). Thechloride and phosphate binding capacity of free amine test polymers,along with the chloride and phosphate binding capacity of free aminesevelamer and bixalomer control polymers, was determined using theselective specific interfering buffer assay (SIB) as follows: The bufferused for the SIB assay comprises 36 mM NaCl, 20 mM NaH₂PO₄, 50 mM2-(N-morpholino)ethanesulfonic acid (MES) buffered to pH 5.5. The SIBbuffer contains concentrations of chloride, phosphate and pH that arepresent in the human duodenum and upper gastrointestinal tract (StevensT, Conwell D L, Zuccaro G, Van Lente F, Khandwala F, Purich E, et al.Electrolyte composition of endoscopically collected duodenal drainagefluid after synthetic porcine secretin stimulation in healthy subjects.Gastrointestinal endoscopy. 2004; 60(3):351-5, Fordtran J, Locklear T.Ionic constituents and osmolality of gastric and small-intestinal fluidsafter eating. Digest Dis Sci. 1966; 11(7):503-21) and is an effectivemeasure of the selectivity of chloride binding compared to phosphatebinding by a polymer. To perform the assay, the free amine polymer beingtested is prepared at a concentration of 2.5 mg/ml (25 mg dry mass) in10 mL of SIB buffer. The mixture is incubated at 37° C. for 1 hour withagitation on a rotisserie mixer. After incubation and mixing, the tubescontaining the polymer are centrifuged for 2 minutes at 1000×g to pelletthe test samples. 750 microliter of supernatant is removed and filteredusing an 800 microliter, 1 micrometer pore-size, 96-well, glass filterplate that has been fitted over a 96-well 2 mL collection plate; withthis arrangement multiple samples tested in SIB buffer can be preparedfor analysis, including the standard controls of free amine sevelamer,free amine bixalomer and a control tube containing blank buffer that isprocessed through all of the assay steps. With the samples arrayed inthe filter plate and the collection plate fitted on the bottom, the unitis centrifuged at 1000×g for 1 minute to filter the samples. In cases ofsmall sample sets, a syringe filter (0.45 micrometer) may be used inlieu of the filter plate, to retrieve ˜2-4 mL of filtrate into a 15 mLvial. After filtration into the collection plate, the respectivefiltrates are diluted before measuring for chloride or phosphatecontent. For the measurement of chloride and phosphate, the filtratesunder analysis are diluted 4× with water. The chloride and phosphatecontent of the filtrate is measured via ion chromatography (IC). The ICmethod (e.g. Dionex ICS-2100, Thermo Scientific) consists of an AS24Acolumn, a 45 mM KOH mobile phase, an injection volume of 5 microliters,with a run time of about 10 minutes, a washing/rinse volume of 1000microliter, and flow rate of 0.3 mL/min. To determine the chloride boundto the polymer, the following calculation is completed:

${{Binding}\mspace{14mu} {capacity}\mspace{14mu} {expressed}\mspace{14mu} {as}\mspace{11mu} {mmol}\mspace{14mu} {chloride}\text{/}g\mspace{14mu} {polymer}} = \frac{\left( {{Cl}_{start} - {Cl}_{final}} \right) \times 4}{2.5}$

where Cl_(star) corresponds to the starting concentration of chloride inthe SIB buffer, Cl_(final) corresponds to the final value of chloride inthe measured diluted filtrates after exposure to the test polymer, 4 isthe dilution factor and 2.5 is the polymer concentration in mg/ml. Todetermine the phosphate bound to the polymer, the following calculationis completed:

${{Binding}\mspace{14mu} {capacity}\mspace{14mu} {expressed}\mspace{14mu} {as}\mspace{11mu} {mmol}\mspace{14mu} {phosphate}\text{/}g\mspace{14mu} {polymer}} = \frac{\left( {P_{start} - P_{final}} \right) \times 4}{2.5}$

where P_(start) corresponds to the starting concentration of phosphatein the SIB buffer, P_(final) corresponds to the final value of phosphatein the measured diluted filtrates after exposure to the test polymer, 4is the dilution factor and 2.5 is the polymer concentration in mg/ml.

“Simulated Small Intestine Organic and Inorganic Buffer” or “SOB” is atest to determine the chloride binding capacity, measured in thepresence of specific organic and inorganic interferents commonly foundin the gastrointestinal tract. The chloride binding capacity, as well asthe binding capacity for other anions, of free amine test polymers andof free amine sevelamer and bixalomer control polymers, was measured inthe presence of specific organic interferents commonly found in thegastrointestinal tract as follows: To mimic the conditions of the GIlumen, the SOB screen is used to determine the chloride binding capacityof free amine polymers when they are exposed to chloride in the presenceof other potential competing anions such as bile acid, fatty acid,phosphate, acetate and citrate. The test buffer used for SOB assaycomprises 50 mM 2-(N-morpholino)ethanesulfonic acid (MES), 50 mM sodiumacetate, 36 mM sodium chloride, 7 mM sodium phosphate, 1.5 mM sodiumcitrate, 30 mM oleic acid and 5 mM Sodium taurocholate, buffered to pH6.2. The concentrations of potential competing anions reflect typicalgastrointestinal lumen concentrations found at various points of the GItract and the pH is an average value representative of pH valuesencountered both the duodenum and the large intestine. The chlorideconcentration used is the same as that used in the SIB screen. Toperform the assay, the free amine polymer to be tested is accuratelyweighed in a 16×100 mm glass tube with a liquid-tight screw cap. Anappropriate amount of SOB buffer is added to the test tube to achieve afinal polymer concentration of 2.5 mg/ml. The mixture is incubated at37° C. for 2 hours with agitation on a rotisserie mixer. Afterincubation and mixing, 600 microliters of supernatant is removed andfiltered using a 96-well glass filter plate. With the samples arrayed inthe filter plate and the collection plate fitted on the bottom, the unitis centrifuged at 1000×g for 1 minute to filter the samples. In cases ofsmall sample sets, a syringe filter may be used in lieu of the filterplate, to retrieve ˜2-4 mL of filtrate into a 15 mL vial. Afterfiltration into the collection plate, the respective filtrates arediluted appropriately before measuring for anion content. The IC method(e.g. Dionex ICS-2100, Thermo Scientific) consists of an AS24A column, aKOH gradient from 20 mM to 100 mM, an injection volume of 5 microliters,with a run time of about 30 minutes, a washing/rinse volume of 1000microliters, and flow rate of 0.3 mL/min. This method is suitable forquantitating chloride, phosphate, and taurocholate. Other appropriatemethods may be substituted. To determine the ions bound to the polymer,the following calculation is completed

${{Binding}\mspace{14mu} {capacity}\mspace{14mu} {expressed}\mspace{14mu} {as}\mspace{11mu} {mmol}\mspace{14mu} {ion}\text{/}g\mspace{14mu} {polymer}} = \frac{\left( {\lbrack{Ion}\rbrack_{start} - \lbrack{Ion}\rbrack_{final}} \right) \times \left\lbrack {{dilution}\mspace{14mu} {factor}} \right\rbrack}{2.5}$

where [Ion]_(start) corresponds to the starting concentration of an ionin the SOB buffer, [Ion]_(final) corresponds to the final value of thatparticular ion in the measured filtrates after exposure to the testpolymer, dilution factor is the dilution factor and 2.5 is the polymerconcentration in mg/ml.

The term “substituted hydrocarbyl,” “substituted alkyl,” “substitutedalkenyl,” “substituted aryl,” “substituted heterocyclo,” or “substitutedheteroaryl” as used herein denotes hydrocarbyl, alkyl, alkenyl, aryl,heterocyclo, or heteroaryl moieties which are substituted with at leastone atom other than carbon and hydrogen, including moieties in which acarbon chain atom is substituted with a hetero atom such as nitrogen,oxygen, silicon, phosphorous, boron, sulfur, or a halogen atom. Thesesubstituents include halogen, heterocyclo, alkoxy, alkenoxy, alkynoxy,aryloxy, hydroxy, keto, acyl, acyloxy, nitro, amino, amido, nitro,cyano, thiol, ketals, acetals, esters and ethers.

“Swelling Ratio” or simply “Swelling” describes the amount of waterabsorbed by a given amount of polymer divided by the weight of thepolymer aliquot. The swelling ratio is expressed as: swelling=(g swollenpolymer−g dry polymer)/g dry polymer. The method used to determine theswelling ratio for any given polymer comprised the following:

-   -   a. 50-100 mg of dry (less than 5 weight % water content) polymer        is placed into an 11 mL sealable test tube (with screw cap) of        known weight (weight of tube=Weight A).    -   b. Deionized water (10 mL) is added to the tube containing the        polymer. The tube is sealed and tumbled for 16 hours (overnight)        at room temperature. After incubation, the tube is centrifuged        at 3000×g for 3 minutes and the supernatant is carefully removed        by vacuum suction. For polymers that form a very loose sediment,        another step of centrifugation is performed.    -   c. After step (b), the weight of swollen polymer plus tube        (Weight B) is recorded. d. Freeze at −40° C. for 30 minutes.        Lyophilize for 48 h. Weigh dried polymer and test tube (recorded        as Weight C).    -   e. Calculate g water absorbed per g of polymer, defined as:        [(Weight B−Weight A)−(Weight C−Weight A)]/(Weight C−Weight A).

A “target ion” is an ion to which the polymer binds, and usually refersto the major ions bound by the polymer, or the ions whose binding to thepolymer is thought to produce the therapeutic effect of the polymer(e.g. proton and chloride binding which leads to net removal of HCl).

The term “theoretical capacity” represents the calculated, expectedbinding of hydrochloric acid in an “SGF” assay, expressed in mmol/g. Thetheoretical capacity is based on the assumption that 100% of the aminesfrom the monomer(s) and crosslinker(s) are incorporated in thecrosslinked polymer based on their respective feed ratios. Theoreticalcapacity is thus equal to the concentration of amine functionalities inthe polymer (mmol/g). The theoretical capacity assumes that each amineis available to bind the respective anions and cations and is notadjusted for the type of amine formed (e.g. it does not subtractcapacity of quaternary amines that are not available to bind proton).

“Therapeutically effective amount” means the amount of a proton-bindingcrosslinked amine polymer that, when administered to a patient fortreating a disease, is sufficient to effect such treatment for thedisease. The amount constituting a “therapeutically effective amount”will vary depending on the polymer, the severity of the disease and theage, weight, etc., of the mammal to be treated.

“Treating” or “treatment” of a disease includes (i) inhibiting thedisease, i.e., arresting or reducing the development of the disease orits clinical symptoms; or (ii) relieving the disease, i.e., causingregression of the disease or its clinical symptoms. Inhibiting thedisease, for example, would include prophylaxis.

The term “triallylamine” denotes an amino moiety having three allylgroups.

The term “vinyl” denotes a moiety having the structural formulaR_(x)H_(y)C═CH—*, where * denotes the point of attachment of the moietyto the remainder of the molecule wherein the point of attachment is aheteroatom or aryl, X and Y are independently 0, 1 or 2, such thatX+Y=2, and R is hydrocarbyl or substituted hydrocarbyl.

The term “weight percent crosslinker” represents the calculatedpercentage, by mass, of a polymer sample that is derived from thecrosslinker. Weight percent crosslinker is calculated using the feedratio of the polymerization, and assumes full conversion of the monomerand crosslinker(s). The mass attributed to the crosslinker is equal tothe expected increase of molecular weight in the infinite polymernetwork after reaction (e.g. 1,3,-dichloropropane is 113 amu, but only42 amu are added to a polymer network after crosslinking with DCPbecause the chlorine atoms, as leaving groups, are not incorporated intothe polymer network).

When introducing elements of the present invention or the preferredembodiments(s) thereof, the articles “a”, “an”, “the” and “said” areintended to mean that there are one or more of the elements. The terms“comprising”, “including” and “having” are intended to be inclusive andnot exclusive (i.e., there may be other elements in addition to therecited elements).

EMBODIMENTS

As previously noted, among the various aspects of the present disclosuremay be noted treatment methods using compositions comprising anonabsorbed, crosslinked polymer containing free amine moieties. In oneembodiment, the crosslinked amine polymers have the capacity to removeclinically significant quantities of protons and chloride ions from thegastrointestinal tract of an animal, including for example humans, uponadministration of a therapeutically effective amount (i.e., an effectivedose) of the crosslinked amine polymer to achieve a therapeutic orprophylactic benefit.

A therapeutically effective dose of the crosslinked amine polymersdisclosed herein will depend, at least in part, on the disease beingtreated, the capacity of the crosslinked free amine polymer, and theintended effect. In one embodiment, the daily dose of the crosslinkedfree amine polymer is sufficient to retard the rate of reduction ofserum bicarbonate levels over a prolonged period. In another embodiment,the daily dose of the crosslinked free amine polymer is sufficient tomaintain serum bicarbonate levels over a prolonged period. In anotherembodiment, the daily dose of the crosslinked free amine polymer issufficient to increase serum bicarbonate levels over a prolonged period.For example, in one embodiment, the daily dose is sufficient to achieveor maintain a serum bicarbonate level of at least about 20 mEq/L over aprolonged period. By way of further example, in one such embodiment, thedaily dose is sufficient to achieve or maintain a serum bicarbonatelevel of at least about 21 mEq/L over a prolonged period. By way offurther example, in one such embodiment, the daily dose is sufficient toachieve or maintain a serum bicarbonate level of at least about 22 mEq/Lover a prolonged period. In yet another embodiment, the daily dose issufficient to achieve or maintain a serum bicarbonate level of at leastabout 24 mEq/L over a prolonged period. In each of the foregoingembodiments, a prolonged period is a period of at least one month; forexample, at least two months, at least three months, or even at leastseveral months.

In general, the dosage levels of the crosslinked amine polymers fortherapeutic and/or prophylactic uses may range from about 0.5 g/day toabout 20 g/day. To facilitate patient compliance, it is generallypreferred that the dose be in the range of about 1 g/day to about 10g/day. For example, in one such embodiment, the dose will be about 2g/day to about 7 g/day. By way of further example, in one suchembodiment, the dose will be about 3 g/day to about 6 g/day. By way offurther example, in one such embodiment, the dose will be about 4 g/dayto about 5 g/day. Optionally, the daily dose may be administered as asingle dose (i.e., one time a day), or divided into multiple doses(e.g., two, three or more doses) over the course of a day. In generalthe crosslinked amine polymers for therapeutic and/or prophylactic usesmay be administered as a fixed daily dose or titrated based on the serumbicarbonate values of the patient in need of treatment or otherindicators of acidosis. The titration may occur at the onset oftreatment or throughout, as required, and starting and maintenancedosage levels may differ from patient to patient based on severity ofthe underlying disease.

As schematically depicted in FIGS. 1A-1C and in accordance with oneembodiment, a non-absorbed, free-amine polymer of the present disclosureis orally ingested and used to treat metabolic acidosis (including byincreasing serum bicarbonate and normalizing blood pH) in a mammal bybinding HCl in the gastrointestinal (“GI”) tract and removing HClthrough the feces. Free-amine polymer is taken orally (FIG. 1A) atcompliance enhancing dose targeted to chronically bind sufficientamounts of HCl to enable clinically meaningful increase in serumbicarbonate of 3 mEq/L. In the stomach (FIG. 1B), free amine becomesprotonated by binding H⁺. Positive charge on polymer is then availableto bind Cl⁻; by controlling access of binding sites through crosslinkingand hydrophilicity/hydrophobicity properties, other larger organicanions (e.g., acetate, propionate, butyrate, etc., depicted as X⁻ andY⁻) are bound to a lesser degree, if at all. The net effect is thereforebinding of HCl. In the lower GI tract/colon (FIG. 1C), Cl⁻ is notreleased and HCl is removed from the body through regular bowel movementand fecal excretion, resulting in net alkalinization in the serum. Cl⁻bound in this fashion is not available for exchange via the Cl⁻/HCO₃antiporter system.

In one embodiment, the polymer is designed to simultaneously maximizeefficacy (net HCl binding and excretion) and minimize GI side effects(through low swelling particle design and particle size distribution).Optimized HCl binding may be accomplished through a careful balance ofcapacity (number of amine binding sites), selectivity (preferred bindingof chloride versus other anions, in particular organic anions in thecolon) and retention (not releasing significant amounts of chloride inthe lower GI tract to avoid the activity of the Cl⁻/HCO₃ exchanger[antiporter] in the colon and intestine; if chloride is not tightlybound to the polymer the Cl⁻/HCO₃ ⁻ exchanger can mediate uptake ofchloride ion from the intestinal lumen and reciprocal exchange forbicarbonate from the serum, thus effectively decreasing serumbicarbonate.

Competing anions that displace chloride lead to a decrease in netbicarbonate through the following mechanisms. First, displacement ofchloride from the polymer in the GI lumen, particularly the colon lumen,provides for a facile exchange with bicarbonate in the serum. The colonhas an anion exchanger (chloride/bicarbonate antiporter) that moveschloride from the luminal side in exchange for secreted bicarbonate.When free chloride is released from the polymer in the GI tract it willexchange for bicarbonate, which will then be lost in the stool and causea reduction in total extracellular bicarbonate (Davis, 1983; D'Agostino,1953). The binding of short chain fatty acids (SCFA) in exchange forbound chloride on the polymer, will result in the depletion ofextracellular HCO3-stores. Short chain fatty acids are the product ofbacterial metabolism of complex carbohydrates that are not catabolizedby normal digestive processes (Chemlarova, 2007). Short chain fattyacids that reach the colon are absorbed and distributed to varioustissues, with the common metabolic fate being the generation of H2O andCO2, which is converted to bicarbonate equivalents. Thus, binding ofSCFA to the polymer to neutralize the proton charge would be detrimentalto overall bicarbonate stores and buffering capacity, necessitating thedesign of chemical and physical features in the polymer that limit SCFAexchange. Finally, phosphate binding to the polymer should be limited aswell, since phosphate represents an additional source of bufferingcapacity in the situation where ammoniagenesis and/or hydrogen ionsecretion is compromised in chronic renal disease.

For each binding of proton, an anion is preferably bound as the positivecharge seeks to leave the human body as a neutral polymer. “Binding” ofan ion, is more than minimal binding, i.e., at least about 0.2 mmol ofion/gm of polymer, at least about 1 mmol of ion/gm of polymer in someembodiments, at least about 1.5 mmol of ion/gm of polymer in someembodiments, and at least about 3 mmol of ion/gm of polymer in someembodiments. In one embodiment, the polymers are characterized by theirhigh capacity of proton binding while at the same time providingselectivity for anions; selectivity for chloride is accomplished byreducing the binding of interfering anions that include but are notlimited to phosphate, citrate, acetate, bile acids and fatty acids. Forexample, in some embodiments, polymers of the present disclosure bindphosphate with a binding capacity of less than about 5 mmol/gm, lessthan about 4 mmol/gm, less than about 3 mmol/gm, less than about 2mmol/gm or even less than about 1 mmol/gm. In some embodiments, polymersof the invention bind bile and fatty acids with a binding capacity ofless than about less than about 5 mmol/g, less than about 4 mmol/g, lessthan about 3 mmol/g, less than about 2 mmol/gm, less than about 1mmol/gm in some embodiments, less than about 0.5 mmol/gm in someembodiments, less than about 0.3 mmol/gm in some embodiments, and lessthan about 0.1 mmol/gm in some embodiments.

The effectiveness of the polymer may be established in animal models, orin human volunteers and patients. In addition, in vitro, ex vivo and invivo approaches are useful to establish HCl binding. In vitro bindingsolutions can be used to measure the binding capacity for proton,chloride and other ions at different pHs. Ex vivo extracts, such as thegastrointestinal lumen contents from human volunteers or from modelanimals can be used for similar purposes. The selectivity of bindingand/or retaining certain ions preferentially over others can also bedemonstrated in such in vitro and ex vivo solutions. In vivo models ofmetabolic acidosis can be used to test the effectiveness of the polymerin normalizing acid/base balance—for example 5/6 nephrectomized rats fedcasein-containing chow (as described in Phisitkul S, Hacker C, Simoni J,Tran R M, Wesson D E. Dietary protein causes a decline in the glomerularfiltration rate of the remnant kidney mediated by metabolic acidosis andendothelin receptors. Kidney international. 2008; 73(2):192-9).

In one embodiment, the polymers described in the current disclosure areprovided to an animal, including a human, in once, twice or three timesa day dosing most preferably not exceeding a daily dose of 5 g or lessper day) to treat metabolic acidosis and achieve a clinicallysignificant and sustained increase of serum bicarbonate of approximately3 mEq/L at these daily doses. The amount of HCl binding achieved by oraladministration of the polymer is determined by the polymer bindingcapacity, which is generally in the range of 5-25 mEq of HCl per 1 g ofpolymer. Additionally, the polymer is preferably selective in terms ofthe anion that is bound to counterbalance the proton binding, withchloride being the preferred anion. Anions other than chloride, bound toneutralize the proton positive charge, include phosphate, short chainfatty acids, long chain fatty acids, bile acids or other organic orinorganic anions. Binding of these anions, other than chloride,influences overall bicarbonate stores in the intracellular andextracellular compartments.

In one embodiment, the mechanism of action for the HCl polymeric bindercomprises the following. In the stomach or elsewhere in the GI tract,the free amine polymer becomes protonated by binding proton (H⁺). Thepositive charge formed as a result of this binding is then available forchloride anion binding. After exiting the stomach, the polymersequentially encounters different GI tract environments in the orderduodenum, jejunum, ileum and colon, each with a complement of distinctorganic and inorganic anions. Physical and chemical properties of thepolymer are designed to control access of protonated binding sites tothis collection of anions. Physical barriers include crosslinking (sizeexclusion to prevent anion binding) and chemical moieties (to repellarger, organic ions such as acetate, propionate, butyrate or othershort chain fatty acids commonly present in the colon), and combinationsof the two properties to limit phosphate, bile acid and fatty acidbinding. By tailoring the bead crosslinking and the chemical nature ofthe amine binding sites, chloride can be bound tightly so that exchangefor other anions and release in the lower GI tract is reduced oreliminated. Without being bound by theory, anions with a larger ionicand/or hydration radius than chloride can be excluded, or their bindingreduced, by incorporating these properties into the HCl binding polymer.For example, the ionic radius of chloride, either in the hydrated orunhydrated form is smaller than the corresponding values for phosphateand other anions commonly encountered in the GI tract lumen(Supramolecular Chemistry, Steed, J W (2009) John Wiley and Sons, page226; Kielland, J (1937), J. Am. Chem. Soc. 59:1675-1678). To selectivelybind smaller ions, polymers typically display high crosslinkingdensities in order to create preferential access to the polymer bindingsites. High crosslinking density materials are, however, typicallycharacterized by low swelling ratios. The swelling ratio, can beaffected by the following composition and process variables: 1) themolar ratio of amine monomer (or polymer) and crosslinker, 2) themonomer+crosslinker to solvent ratio in the crosslinking reaction, 3)the net charge of the polymer (at the physiological pH and tonicity ofthe milieu in which it will be used), 4) the hydrophilic/hydrophobicbalance of the backbone polymer and/or 5) post-crosslinking of anexisting material.

In general, a crosslinked amine polymer of the present disclosure istypically characterized by a low swelling ratio. In one embodiment, therelative chloride binding to phosphate binding ratio in SIB is anindicator of the selectivity of the crosslinked polymers of the currentdisclosure for chloride versus larger anions. A graph of therelationship between swelling ratios for certain polymers of the currentdisclosure versus the chloride:phosphate binding ratio in SIB is shownin FIG. 2. For example, in one embodiment, a polymer of the currentdisclosure has a chloride to phosphate binding ratio in SIB of ≥0.35 anda swelling ratio of ≤2 g water per g of dry polymer. By way of furtherexample, in one embodiment a polymer of the current disclosure has achloride to phosphate binding ratio in SIB of ≥0.5 and a swelling ratioof ≤2 g water per g of dry polymer. By way of further example, in oneembodiment a polymer of the current disclosure has a chloride tophosphate binding ratio in SIB of ≥1 and a swelling ratio of ≤2 g waterper g of dry polymer. By way of further example, in one embodiment apolymer of the current disclosure has a chloride to phosphate bindingratio in SIB of ≥2 and a swelling ratio of ≤2 g water per g of drypolymer. By way of further example, in one embodiment a polymer of thecurrent disclosure has a chloride to phosphate binding ratio in SIB of≥0.35 and a swelling ratio of 1 g water per g of dry polymer. By way offurther example, in one embodiment a polymer of the current disclosurehas a chloride to phosphate binding ratio in SIB of ≥0.5 and a swellingratio of ≤1 g water per g of dry polymer. By way of further example, inone embodiment a polymer of the current disclosure has a chloride tophosphate binding ratio in SIB of ≥1 and a swelling ratio of ≤1 g waterper g of dry polymer. By way of further example, in one embodiment apolymer of the current disclosure has a chloride to phosphate bindingratio in SIB of ≥2 and a swelling ratio of ≤1 g water per g of drypolymer.

In some embodiments, a crosslinked amine polymer of the currentdisclosure versus the chloride:phosphate binding ratio in SIB is shownin FIG. 2. For example, in one embodiment a polymer of the currentdisclosure has a chloride binding capacity in SGF of ≥10 mmol/g and aswelling ratio of ≤2 g water per g of dry polymer. By way of furtherexample, in one embodiment a polymer of the current disclosure has achloride binding capacity in SGF of ≥12 mmol/g and a swelling ratio of≤2 g water per g of dry polymer. By way of further example, in oneembodiment a polymer of the current disclosure has a chloride bindingcapacity in SGF of ≥14 mmol/g and a swelling ratio of ≤2 g water per gof dry polymer. By way of further example, in one embodiment a polymerof the current disclosure has a chloride binding capacity in SGF of ≥10mmol/g and a swelling ratio of ≤1.5 g water per g of dry polymer. By wayof further example, in one embodiment a polymer of the currentdisclosure has a chloride binding capacity in SGF of ≥12 mmol/g and aswelling ratio of ≤1.5 g water per g of dry polymer. By way of furtherexample, in one embodiment a polymer of the current disclosure has achloride binding capacity in SGF of ≥14 mmol/g and a swelling ratio of≤1.5 g water per g of dry polymer.

In some embodiments, the theoretical chloride binding capacity of thepolymers of the present disclosure may range from about 1 mmol/g toabout 25 mmol/g. In one embodiment, the theoretical chloride bindingcapacity of the polymer is about 3 mmol/g to about 25 mmol/g. In anotherembodiment, the theoretical chloride binding capacity of the polymer isabout 6 mmol/g to about 20 mmol/g. In another embodiment, thetheoretical chloride binding capacity of the polymer about 9 mmol/g toabout 17 mmol/g.

In some embodiments, the molecular weight per nitrogen of the polymersof the present disclosure may range from about 40 to about 1000 daltons.In one embodiment, the molecular weight per nitrogen of the polymer isfrom about 40 to about 500 daltons. In another embodiment, the molecularweight per nitrogen of the polymer is from about 50 to about 170daltons. In another embodiment, the molecular weight per nitrogen of thepolymer is from about 60 to about 110 daltons.

In some embodiments, the crosslinker weight % range will be about 10 to90 weight % of the crosslinked amine polymer. For example, in someembodiments the crosslinker weight % range will be about 15 to 90 weight% of the crosslinked amine polymer or even about 25 to 90 weight % ofthe crosslinked amine polymer.

The crosslinked amine polymers may be prepared using a range ofchemistries, including for example, (i) substitution polymerization ofpolyfunctional reagents at least one of which comprises amine moieties,(2) radical polymerization of a monomer comprising at least one aminemoiety or nitrogen containing moiety, and (3) crosslinking of anamine-containing intermediate with a polyfunctional crosslinker,optionally containing amine moieties. The resulting crosslinked polymersmay thus, for example, be crosslinked homopolymers or crosslinkedcopolymers. By way of further example, the resulting crosslinkedpolymers will typically possess repeat units comprising free aminemoieties, separated by the same or varying lengths of repeating linker(or intervening) units. In some embodiments, the polymers compriserepeat units comprising an amine moiety and an intervening linker unit.In other embodiments, multiple amine-containing repeat units areseparated by one or more linker units. Additionally, the polyfunctionalcrosslinkers may comprise HCl binding functional groups, e.g. amines,(“active crosslinkers”) or may lack HCl binding functional groups suchas amines (“passive crosslinkers”).

In some embodiments, an amine-containing monomer is polymerized and thepolymer is concurrently crosslinked in a substitution polymerizationreaction. The amine reactant (monomer) in the concurrent polymerizationand crosslinking reaction can react more than one time for thesubstitution polymerization. In one such embodiment, the amine monomeris a linear amine possessing at least two reactive amine moieties toparticipate in the substitution polymerization reaction. In anotherembodiment, the amine monomer is a branched amine possessing at leasttwo reactive amine moieties to participate in the substitutionpolymerization reaction. Crosslinkers for the concurrent substitutionpolymerization and crosslinking typically have at least twoamine-reactive moieties such as alkyl-chlorides, and alkyl-epoxides. Inorder to be incorporated into the polymer, primary amines react at leastonce and potentially may react up to three times with the crosslinker,secondary amines can react up to twice with the crosslinkers, andtertiary amines can only react once with the crosslinker. In general,however, and in accordance with one aspect of the present disclosure,the formation of a significant number of quaternary nitrogens/amines isgenerally not preferred because quaternary amines cannot bind protons.

Exemplary amines that may be used in substitution polymerizationreactions described herein include1,3-Bis[bis(2-aminoethyl)amino]propane,3-Amino-1-{[2-(bis{2-[bis(3-aminopropyl)amino]ethyl}amino)ethyl](3-aminopropyl)amino}propane,2-[Bis(2-aminoethyl)amino]ethanamine, Tris(3-aminopropyl)amine,1,4-Bis[bis(3-aminopropyl)amino]butane, 1,2-Ethanediamine,2-Amino-1-(2-aminoethylamino)ethane, 1,2-Bis(2-aminoethylamino)ethane,1,3-Propanediamine, 3,3′-Diaminodipropylamine,2,2-dimethyl-1,3-propanediamine, 2-methyl-1,3-propanediamine,N,N′-dimethyl-1,3-propanediamine, N-methyl-1,3-diaminopropane,3,3′-diamino-N-methyldipropylamine, 1,3-diaminopentane,1,2-diamino-2-methylpropane, 2-methyl-1,5-diaminopentane,1,2-diaminopropane, 1,10-diaminodecane, 1,8-diaminooctane,1,9-diaminooctane, 1,7-diaminoheptane, 1,6-diaminohexane,1,5-diaminopentane, 3-bromopropylamine hydrobromide,N,2-dimethyl-1,3-propanediamine, N-isopropyl-1,3-diaminopropane,N,N′-bis(2-aminoethyl)-1,3-propanediamine,N,N′-bis(3-aminopropyl)ethylenediamine,N,N′-bis(3-aminopropyl)-1,4-butanediamine tetrahydrochloride,1,3-diamino-2-propanol, N-ethylethylenediamine,2,2′-diamino-N-methyldiethylamine, N,N′-diethylethylenediamine,N-isopropylethylenediamine, N-methylethylenediamine,N,N′-di-tert-butylethylenediamine, N,N′-diisopropylethylenediamine,N,N′-dimethylethylenediamine, N-butylethylenediamine,2-(2-aminoethylamino)ethanol, 1,4,7,10,13,16-hexaazacyclooctadecane,1,4,7,10-tetraazacyclododecane, 1,4,7-triazacyclononane,N,N′-bis(2-hydroxyethyl)ethylenediamine, piperazine,bis(hexamethylene)triamine, N-(3-hydroxypropyl)ethylenediamine,N-(2-Aminoethyl)piperazine, 2-Methylpiperazine, Homopiperazine,1,4,8,11-Tetraazacyclotetradecane, 1,4,8,12-Tetraazacyclopentadecane,2-(Aminomethyl)piperidine, 3-(Methylamino)pyrrolidine

Exemplary crosslinking agents that may be used in substitutionpolymerization reactions and post-polymerization crosslinking reactionsinclude include, but are not limited to, one or more multifunctionalcrosslinking agents such as: dihaloalkanes, haloalkyloxiranes,alkyloxirane sulfonates, di(haloalkyl)amines, tri(haloalkyl) amines,diepoxides, triepoxides, tetraepoxides, bis (halomethyl)benzenes,tri(halomethyl)benzenes, tetra(halomethyl)benzenes, epihalohydrins suchas epichlorohydrin and epibromohydrin poly(epichlorohydrin),(iodomethyl)oxirane, glycidyl tosylate, glycidyl3-nitrobenzenesulfonate, 4-tosyloxy-1,2-epoxybutane,bromo-1,2-epoxybutane, 1,2-dibromoethane, 1,3-dichloropropane,1,2-dichloroethane, I-bromo-2-chloroethane, 1,3-dibromopropane,bis(2-chloroethyl)amine, tris(2-chloroethyl)amine, andbis(2-chloroethyl)methylamine, 1,3-butadiene diepoxide, 1,5-hexadienediepoxide, diglycidyl ether, 1,2,7,8-diepoxyoctane,1,2,9,10-diepoxydecane, ethylene glycol diglycidyl ether, propyleneglycol diglycidyl ether, 1,4-butanediol diglycidyl ether, 1,2ethanedioldiglycidyl ether, glycerol diglycidyl ether, 1,3-diglycidylglyceryl ether, N,N-diglycidylaniline, neopentyl glycol diglycidylether, diethylene glycol diglycidyl ether, 1,4-bis(glycidyloxy)benzene,resorcinol digylcidyl ether, 1,6-hexanediol diglycidyl ether,trimethylolpropane diglycidyl ether, 1,4-cyclohexanedimethanoldiglycidyl ether,1,3-bis-(2,3-epoxypropyloxy)-2-(2,3-dihydroxypropyloxy)propane,1,2-cyclohexanedicarboxylic acid diglycidyl ester, 2,2′-bis(glycidyloxy)diphenylmethane, bisphenol F diglycidyl ether, 1,4-bis(2′,3′epoxypropyl)perfluoro-n-butane, 2,6-di(oxiran-2-ylmethyl)-1,2,3,5,6,7-hexahydropyrrolo[3,4-f]isoindol-1,3,5,7-tetraone,bisphenol A diglycidyl ether, ethyl5-hydroxy-6,8-di(oxiran-2-ylmethyl)-4-oxo-4-h-chromene-2-carboxylate,bis[4-(2,3-epoxy-propylthio )phenyl]-sulfide, 1,3-bis(3-glycidoxypropyl)tetramethyldisiloxane, 9,9-bis[4-(glycidyloxy)phenyl]fluorine,triepoxyisocyanurate, glycerol triglycidyl ether,N,N-diglycidyl-4-glycidyloxyaniline, isocyanuric acid(S,S,S)-triglycidyl ester, isocyanuric acid (R,R,R)-triglycidyl ester,triglycidyl isocyanurate, trimethylolpropane triglycidyl ether, glycerolpropoxylate triglycidyl ether, triphenylolmethane triglycidyl ether,3,7,14-tris[[3-(epoxypropoxy)propyl]dimethylsilyloxy]-1,3,5,7,9,11,14-heptacyclopentyltricyclo[7,3,3,15,11]heptasiloxane, 4,4′ methylenebis(N,N-diglycidylaniline),bis(halomethyl)benzene, bis(halomethyl)biphenyl andbis(halomethyl)naphthalene, toluene diisocyanate, acrylol chloride,methyl acrylate, ethylene bisacrylamide, pyrometallic dianhydride,succinyl dichloride, dimethylsuccinate,3-chloro-1-(3-chloropropylamino-2-propanol,1,2-bis(3-chloropropylamino)ethane, Bis(3-chloropropyl)amine,1,3-Dichloro-2-propanol, 1,3-Dichloropropane, 1-chloro-2,3-epoxypropane,tris[(2-oxiranyl)methyl]amine.

For the radical polymerization, the amine monomer will typically be amono-functional vinyl, allyl, or acrylamide (e.g., allylamine) andcrosslinkers will have two or more vinyl, allyl or acrylamidefunctionalities (e.g., diallylamine). Concurrent polymerization andcrosslinking occurs through radically initiated polymerization of amixture of the mono- and multifunctional allylamines. The resultingpolymer network is thusly crosslinked through the carbon backbone. Eachcrosslinking reaction forms a carbon-carbon bond (as opposed tosubstitution reactions in which a carbon-heteroatom bond is formedduring crosslinking). During the concurrent polymerization andcrosslinking, the amine functionalities of the monomers do not undergocrosslinking reactions and are preserved in the final polymer (i.e.,primary amines remain primary, secondary amines remain secondary, andtertiary amines remain tertiary).

In those embodiments in which the preparation of the polymers comprisesradical polymerization, a wide range of initiators may be used includingcationic and radical initiators. Some examples of suitable initiatorsthat may be used include: the free radical peroxy and azo typecompounds, such as azodiisobutyronitrile, azodiisovaleronitrile,dimethylazodiisobutyrate, 2,2′azo bis(isobutyronitrile),2,2′-azobis(N,N′-dimethyl-eneisobutyramidine)dihydrochloride,2,2′-azobis(2-amidinopropane)dihydrochloride,2,2′-azobis(N,N′-dimethyleneisobutyramidine), 1,1′-azobis(I-cyclohexanecarbo-nitrile), 4,4′-azobis(4-cyanopentanoic acid),2,2′-azobis(isobutyramide)dihydrate, 2,2′-azobis(2-methylpropane),2,2′-azobis(2-methylbutyronitrile), VAZO 67, cyanopentanoic acid, theperoxypivalates, dodecylbenzene peroxide, benzoyl peroxide, di-t-butylhydroperoxide, t-butyl peracetate, acetyl peroxide, dicumyl peroxide,cumylhydroperoxide, dimethyl bis(butylperoxy)hexane.

In some embodiments, the crosslinked amine polymer comprises the residueof an amine corresponding to Formula 1:

wherein R₁, R₂ and R₃ are independently hydrogen, hydrocarbyl,substituted hydrocarbyl provided, however, at least one of R₁, R₂ and R₃is other than hydrogen. Stated differently, at least one of R₁, R₂ andR₃ is hydrocarbyl or substituted hydrocarbyl, and the others of R₁, R₂and R₃ are independently hydrogen, hydrocarbyl, or substitutedhydrocarbyl. In one embodiment, for example, R₁, R₂ and R₃ areindependently hydrogen, aryl, aliphatic, heteroaryl, or heteroaliphaticprovided, however, each of R₁, R₂ and R₃ are not hydrogen. By way offurther example, in one such embodiment R₁, R₂ and R₃ are independentlyhydrogen, saturated hydrocarbons, unsaturated aliphatic, unsaturatedheteroaliphatic, heteroalkyl, heterocyclic, aryl or heteroaryl,provided, however, each of R₁, R₂ and R₃ are not hydrogen. By way offurther example, in one such embodiment R₁, R₂ and R₃ are independentlyhydrogen, alkyl, alkenyl, allyl, vinyl, aryl, aminoalkyl, alkanol,haloalkyl, hydroxyalkyl, ethereal, heteroaryl or heterocyclic provided,however, each of R₁, R₂ and R₃ are not hydrogen. By way of furtherexample, in one such embodiment R₁, R₂ and R₃ are independentlyhydrogen, alkyl, aminoalkyl, alkanol, aryl, haloalkyl, hydroxyalkyl,ethereal, heteroaryl or heterocyclic provided, however, each of R₁, R₂and R₃ are not hydrogen. By way of further example, in one suchembodiment R₁ and R₂ (in combination with the nitrogen atom to whichthey are attached) together constitute part of a ring structure, so thatthe monomer as described by Formula 1 is a nitrogen-containingheterocycle (e.g., piperidine) and R₃ is hydrogen, or heteroaliphatic.By way of further example, in one embodiment R₁, R₂ and R₃ areindependently hydrogen, aliphatic or heteroaliphatic provided, however,at least one of R₁, R₂ and R₃ is other than hydrogen. By way of furtherexample, in one embodiment R₁, R₂ and R₃ are independently hydrogen,allyl, or aminoalkyl.

In one embodiment, the crosslinked amine polymer comprises the residueof an amine corresponding to Formula 1 wherein R₁, R₂, and R₃ areindependently hydrogen, heteroaryl, aryl, aliphatic or heteroaliphaticprovided, however, at least one of R₁, R₂, and R₃ is aryl or heteroaryl.For example, in this embodiment R₁ and R₂, in combination with thenitrogen atom to which they are attached, may form a saturated orunsaturated nitrogen-containing heterocyclic ring. By way of furtherexample, R₁ and R₂, in combination with the nitrogen atom to which theyare attached may constitute part of a pyrrolidino, pyrole, pyrazolidine,pyrazole, imidazolidine, imidazole, piperidine, pyridine, piperazine,diazine, or triazine ring structure. By way of further example, R₁ andR₂, in combination with the nitrogen atom to which they are attached mayconstitute part of a piperidine ring structure.

In one embodiment, the crosslinked amine polymer comprises the residueof an amine corresponding to Formula 1 wherein R₁, R₂, and R₃ areindependently hydrogen, aliphatic, or heteroaliphatic provided, however,at least one of R₁, R₂, and R₃ is other than hydrogen. For example, inthis embodiment R₁, R₂, and R₃ may independently be hydrogen, alkyl,alkenyl, allyl, vinyl, aminoalkyl, alkanol, haloalkyl, hydroxyalkyl,ethereal, or heterocyclic provided, however, at least one of R₁, R₂, andR₃ is other than hydrogen. By way of further example, in one suchembodiment R₁ and R₂, in combination with the nitrogen atom to whichthey are attached, may form a saturated or unsaturatednitrogen-containing heterocyclic ring. By way of further example, in onesuch embodiment R₁ and R₂, in combination with the nitrogen atom towhich they are attached may constitute part of a pyrrolidino, pyrole,pyrazolidine, pyrazole, imidazolidine, imidazole, piperidine,piperazine, or diazine ring structure. By way of further example, in onesuch embodiment R₁ and R₂, in combination with the nitrogen atom towhich they are attached may constitute part of a piperidine ringstructure. By way of further example, in one such embodiment the aminecorresponding to Formula 1 is acyclic and at least one of R₁, R₂, and R₃is aliphatic or heteroaliphatic. By way of further example, in one suchembodiment R₁, R₂, and R₃ are independently hydrogen, alkyl, allyl,vinyl, alicyclic, aminoalkyl, alkanol, or heterocyclic, provided atleast one of R₁, R₂, and R₃ is other than hydrogen.

In one embodiment, the crosslinked amine polymer comprises the residueof an amine corresponding to Formula 1 and the crosslinked amine polymeris prepared by substitution polymerization of the amine corresponding toFormula 1 with a polyfunctional crosslinker (optionally also comprisingamine moieties) wherein R₁, R₂, and R₃ are independently hydrogen,alkyl, aminoalkyl, or alkanol, provided at least one of R₁, R₂, and R₃is other than hydrogen.

In some embodiments, the crosslinked amine polymer comprises the residueof an amine corresponding to Formula 1a and the crosslinked aminepolymer is prepared by radical polymerization of an amine correspondingto Formula 1a:

wherein R₄ and R₅ are independently hydrogen, hydrocarbyl, orsubstituted hydrocarbyl. In one embodiment, for example, R₄ and R₅ areindependently hydrogen, saturated hydrocarbon, unsaturated aliphatic,aryl, heteroaryl, unsaturated heteroaliphatic, heterocyclic, orheteroalkyl. By way of further example, in one such embodiment R₄ and R₅are independently hydrogen, aliphatic, heteroaliphatic, aryl, orheteroaryl. By way of further example, in one such embodiment R₄ and R₅are independently hydrogen, alkyl, alkenyl, allyl, vinyl, aryl,aminoalkyl, alkanol, haloalkyl, hydroxyalkyl, ethereal, heteroaryl orheterocyclic. By way of further example, in one such embodiment R₄ andR₅ are independently hydrogen, alkyl, allyl, aminoalkyl, alkanol, aryl,haloalkyl, hydroxyalkyl, ethereal, or heterocyclic. By way of furtherexample, in one such embodiment R₄ and R₅ (in combination with thenitrogen atom to which they are attached) together constitute part of aring structure, so that the monomer as described by Formula 1a is anitrogen-containing heterocycle (e.g., piperidine). By way of furtherexample, in one embodiment R₄ and R₅ are independently hydrogen,aliphatic or heteroaliphatic. By way of further example, in oneembodiment R₄ and R₅ are independently hydrogen, allyl, or aminoalkyl.

In some embodiments, the crosslinked amine polymer comprises the residueof an amine corresponding to Formula 1b and the crosslinked aminepolymer is prepared by substitution polymerization of the aminecorresponding to Formula 1b with a polyfunctional crosslinker(optionally also comprising amine moieties):

wherein R₄ and R₅ are independently hydrogen, hydrocarbyl, orsubstituted hydrocarbyl, R₆ is aliphatic and R₆₁ and R₆₂ areindependently hydrogen, aliphatic, or heteroaliphatic. In oneembodiment, for example, R₄ and R₅ are independently hydrogen, saturatedhydrocarbon, unsaturated aliphatic, aryl, heteroaryl, heteroalkyl, orunsaturated heteroaliphatic. By way of further example, in one suchembodiment R₄ and R₅ are independently hydrogen, aliphatic,heteroaliphatic, aryl, or heteroaryl. By way of further example, in onesuch embodiment R₄ and R₅ are independently hydrogen, alkyl, alkenyl,allyl, vinyl, aryl, aminoalkyl, alkanol, haloalkyl, hydroxyalkyl,ethereal, heteroaryl or heterocyclic. By way of further example, in onesuch embodiment R₄ and R₅ are independently hydrogen, alkyl, alkenyl,aminoalkyl, alkanol, aryl, haloalkyl, hydroxyalkyl, ethereal, heteroarylor heterocyclic. By way of further example, in one such embodiment R₄and R₅ (in combination with the nitrogen atom to which they areattached) together constitute part of a ring structure, so that themonomer as described by Formula 1a is a nitrogen-containing heterocycle(e.g., piperidine). By way of further example, in one embodiment R₄ andR₅ are independently hydrogen, aliphatic or heteroaliphatic. By way offurther example, in one embodiment R₄ and R₅ are independently hydrogen,allyl, or aminoalkyl. By way of further example, in each of theembodiments recited in this paragraph, R₆ may be methylene, ethylene orpropylene, and R₆₁ and R₆₂ may independently be hydrogen, allyl oraminoalkyl.

In some embodiments, the crosslinked amine polymer comprises the residueof an amine corresponding to Formula 1c:

wherein R₇ is hydrogen, aliphatic or heteroaliphatic and R₈ is aliphaticor heteroaliphatic. For example, in one such embodiment, for example, R₇is hydrogen and R₈ is aliphatic or heteroaliphatic. By way of furtherexample, in one such embodiment R₇ and R₈ are independently aliphatic orheteroaliphatic. By way of further example, in one such embodiment atleast one of R₇ and R₈ comprises an allyl moiety. By way of furtherexample, in one such embodiment at least one of R₇ and R₈ comprises anaminoalkyl moiety. By way of further example, in one such embodiment R₇and R₈ each comprise an allyl moiety. By way of further example, in onesuch embodiment R₇ and R₈ each comprise an aminoalkyl moiety. By way offurther example, in one such embodiment R₇ comprises an allyl moiety andR₈ comprises an aminoalkyl moiety.

In some embodiments, the crosslinked amine polymer comprises the residueof an amine corresponding to Formula 2:

wherein

m and n are independently non-negative integers;

R₁₀, R₂₀, R₃₀, and R₄₀ are independently hydrogen, hydrocarbyl, orsubstituted hydrocarbyl;

X₁ is

X₂ is hydrocarbyl or substituted hydrocarbyl;

each X₁₁ is independently hydrogen, hydrocarbyl, substitutedhydrocarbyl, hydroxyl, amino, boronic acid, or halo; and

z is a non-negative number.

In one embodiment, the crosslinked amine polymer comprises the residueof an amine corresponding to Formula 2, the crosslinked amine polymer isprepared by (i) substitution polymerization of the amine correspondingto Formula 2 with a polyfunctional crosslinker (optionally alsocomprising amine moieties) or (2) radical polymerization of an aminecorresponding to Formula 2, and m and n are independently 0, 1, 2 or 3and n is 0 or 1.

In one embodiment, the crosslinked amine polymer comprises the residueof an amine corresponding to Formula 2, the crosslinked amine polymer isprepared by (i) substitution polymerization of the amine correspondingto Formula 2 with a polyfunctional crosslinker (optionally alsocomprising amine moieties) or (2) radical polymerization of an aminecorresponding to Formula 2, and R₁₀, R₂₀, R₃₀, and R₄₀ are independentlyhydrogen, aliphatic, aryl, heteroaliphatic, or heteroaryl. By way offurther example, in one such embodiment R₁₀, R₂₀, R₃₀, and R₄₀ areindependently hydrogen, aliphatic, or heteroaliphatic. By way of furtherexample, in one such embodiment R₁₀, R₂₀, R₃₀, and R₄₀ are independentlyhydrogen, alkyl, allyl, vinyl, or aminoalkyl. By way of further example,in one such embodiment R₁₀, R₂₀, R₃₀, and R₄₀ are independentlyhydrogen, alkyl, allyl, vinyl, —(CH₂)_(d)NH₂,—(CH₂)_(d)N[(CH₂)_(e)NH₂)]₂ where d and e are independently 2-4. In eachof the foregoing exemplary embodiments of this paragraph, m and z mayindependently be 0, 1, 2 or 3 and n is 0 or 1.

In one embodiment, the crosslinked amine polymer comprises the residueof an amine corresponding to Formula 2, the crosslinked amine polymer isprepared by (i) substitution polymerization of the amine correspondingto Formula 2 with a polyfunctional crosslinker (optionally alsocomprising amine moieties) or (2) radical polymerization of an aminecorresponding to Formula 2, and X₂ is aliphatic or heteroaliphatic. Forexample, in one such embodiment X₂ is aliphatic or heteroaliphatic andR₁₀, R₂₀, R₃₀, and R₄₀ are independently hydrogen, aliphatic,heteroaliphatic. By way of further example, in one such embodiment X₂ isalkyl or aminoalkyl and R₁₀, R₂₀, R₃₀, and R₄₀ are independentlyhydrogen, aliphatic, or heteroaliphatic. By way of further example, inone such embodiment X₂ is alkyl or aminoalkyl and R₁₀, R₂₀, R₃₀, and R₄₀are independently hydrogen, alkyl, allyl, vinyl, or aminoalkyl. In eachof the foregoing exemplary embodiments of this paragraph, m and z mayindependently be 0, 1, 2 or 3 and n is 0 or 1.

In one embodiment, the crosslinked amine polymer comprises the residueof an amine corresponding to Formula 2, the crosslinked amine polymer isprepared by (i) substitution polymerization of the amine correspondingto Formula 2 with a polyfunctional crosslinker (optionally alsocomprising amine moieties) or (2) radical polymerization of an aminecorresponding to Formula 2, and m is a positive integer. For example, inone such embodiment m is a positive integer, z is zero and R₂₀ ishydrogen, aliphatic or heteroaliphatic. By way of further example, inone such embodiment m is a positive integer (e.g., 1 to 3), z is apositive integer (e.g., 1 to 2), X₁₁ is hydrogen, aliphatic orheteroaliphatic, and R₂₀ is hydrogen, aliphatic or heteroaliphatic. Byway of further example, in one such embodiment m is a positive integer,z is zero, one or two, X₁₁ is hydrogen alkyl, alkenyl, or aminoalkyl,and R₂₀ is hydrogen, alkyl, alkenyl, or aminoalkyl.

In one embodiment, the crosslinked amine polymer comprises the residueof an amine corresponding to Formula 2, the crosslinked amine polymer isprepared by (i) substitution polymerization of the amine correspondingto Formula 2 with a polyfunctional crosslinker (optionally alsocomprising amine moieties) or (2) radical polymerization of an aminecorresponding to Formula 2, and n is a positive integer and R₃₀ ishydrogen, aliphatic or heteroaliphatic. By way of further example, inone such embodiment n is 0 or 1, and R₃₀ is hydrogen, alkyl, alkenyl, oraminoalkyl.

In one embodiment, the crosslinked amine polymer comprises the residueof an amine corresponding to Formula 2, the crosslinked amine polymer isprepared by (i) substitution polymerization of the amine correspondingto Formula 2 with a polyfunctional crosslinker (optionally alsocomprising amine moieties) or (2) radical polymerization of an aminecorresponding to Formula 2, and m and n are independently non-negativeintegers and X₂ is aliphatic or heteroaliphatic. For example, in onesuch embodiment m is 0 to 2, n is 0 or 1, X₂ is aliphatic orheteroaliphatic, and R₁₀, R₂₀, R₃₀, and R₄₀ are independently hydrogen,aliphatic, or heteroaliphatic. By way of further example, in one suchembodiment m is 0 to 2, n is 0 or 1, X₂ is alkyl or aminoalkyl, and R₁₀,R₂₀, R₃₀, and R₄₀ are independently hydrogen, aliphatic, orheteroaliphatic. By way of further example, in one such embodiment m is0 to 2, n is 0 or 1, X₂ is alkyl or aminoalkyl, and R₁₀, R₂₀, R₃₀, andR₄₀ are independently hydrogen, alkyl, alkenyl, or aminoalkyl.

In some embodiments, the crosslinked amine polymer comprises the residueof an amine corresponding to Formula 2a and the crosslinked aminepolymer is prepared by substitution polymerization of the aminecorresponding to Formula 2a with a polyfunctional crosslinker(optionally also comprising amine moieties):

wherein

m and n are independently non-negative integers;

each R₁₁ is independently hydrogen, hydrocarbyl, heteroaliphatic, orheteroaryl;

R₂₁ and R₃₁, are independently hydrogen or heteroaliphatic;

R₄₁ is hydrogen, substituted hydrocarbyl, or hydrocarbyl;

X₁ is

X₂ is alkyl or substituted hydrocarbyl;

each X₁₂ is independently hydrogen, hydroxy, amino, aminoalkyl, boronicacid or halo; and

z is a non-negative number.

In one embodiment, the crosslinked amine polymer comprises the residueof an amine corresponding to Formula 2a, the crosslinked amine polymeris prepared by substitution polymerization of the amine corresponding toFormula 1 with a polyfunctional crosslinker (optionally also comprisingamine moieties). For example, in one such embodiment, m and z areindependently 0, 1, 2 or 3, and n is 0 or 1.

In one embodiment, the crosslinked amine polymer comprises the residueof an amine corresponding to Formula 2a, the crosslinked amine polymeris prepared by substitution polymerization of the amine corresponding toFormula 2a with a polyfunctional crosslinker (optionally also comprisingamine moieties), and each R₁₁ is independently hydrogen, aliphatic,aminoalkyl, haloalkyl, or heteroaryl, R₂₁ and R₃₁ are independentlyhydrogen or heteroaliphatic and R₄₁ is hydrogen, aliphatic, aryl,heteroaliphatic, or heteroaryl. For example, in one such embodiment eachR₁₁ is hydrogen, aliphatic, aminoalkyl, or haloalkyl, R₂₁ and R₃₁ areindependently hydrogen or heteroaliphatic and R₄₁ is hydrogen,alkylamino, aminoalkyl, aliphatic, or heteroaliphatic. By way of furtherexample, in one such embodiment each R₁₁ is hydrogen, aliphatic,aminoalkyl, or haloalkyl, R₂₁ and R₃₁ are hydrogen or aminoalkyl, andR₄₁ is hydrogen, aliphatic, or heteroaliphatic. By way of furtherexample, in one such embodiment each R₁₁ and R₄₁ is independentlyhydrogen, alkyl, or aminoalkyl, and R₂₁ and R₃₁ are independentlyhydrogen or heteroaliphatic. By way of further example, in one suchembodiment each R₁₁ and R₄₁ is independently hydrogen, alkyl,—(CH₂)_(d)NH₂, —(CH₂)_(d)N[(CH₂)_(e)NH₂)]₂ where d and e areindependently 2-4, and R₂₁ and R₃₁ are independently hydrogen orheteroaliphatic. In each of the foregoing exemplary embodiments of thisparagraph, m and z may independently be 0, 1, 2 or 3, and n is 0 or 1.

Exemplary amines for the synthesis of polymers comprising repeat unitscorresponding to Formula 2a include, but are not limited to, aminesappearing in Table 1.

TABLE 1 Abbreviation IUPAC name Other names MW (g/mol) C2A3BTA1,3-Bis[bis(2- aminoethyl)amino] propane

288.48 C2A3G2 3-Amino-1-{[2- (bis{2-[bis(3- aminopropyl) amino]ethyl}amino)ethyl](3- aminopropyl) amino}propane

488.81 C2PW 2-[Bis(2- aminoethyl)amino] ethanamine 2,2′,2″-Triaminotriethylamine or 2,2′,2″- Nitrilotriethylamine

146.24 C3PW Tris(3- aminopropyl)amine

188.32 C4A3BTA 1,4-Bis[bis(3- aminopropyl) amino]butane

316.54 EDA1 1,2-Ethanediamine

60.1 EDA2 2-Amino-1-(2- aminoethylamino) ethane Bis(2- aminoethyl)amineor 2,2′- Diaminodiethylamine

103.17 EDA3 1,2-Bis(2- aminoethylamino) ethane N,N′-Bis(2-aminoethyl)ethane- 1,2-diamine

146.24 PDA1 1,3- Propanediamine

74.3 PDA2 3,3′-Diamino- dipropylamine

131.22

Exemplary crosslinkers for the synthesis of polymers comprising theresidue of amines corresponding to Formula 2a include but are notlimited to crosslinkers appearing in Table 2.

TABLE 2 MW Abbreviation Common name IUPAC name (g/mol) BCPABis(3-chloropropyl)amine Bis(3-chloropropyl)amine

206.54 DC2OH 1,3-dichloroisopropanol 1,3-Dichloro-2-propanol

128.98 DCP Dichloropropane 1,3-Dichloropropane

112.98 ECH Epichlorohydrin 1-chloro-2,3- epoxypropane

 92.52 TGA Triglycidyl amine Tris[(2- oxiranyl)methyl]amine

185.22 BCPOH Bis(3-chloropropyl)amine-OH 3-Chloro-1-(3-chloropropylamino)-2- propanol

186.08 BCPEDA Bis(chloropropyl)ethylenediamine 1,2-Bis(3-chloropropylamino)ethane

213.15

In some embodiments, the crosslinked amine polymer comprises the residueof an amine corresponding to Formula 2b and the crosslinked aminepolymer is prepared by radical polymerization of an amine correspondingto Formula 2b:

wherein

m and n are independently non-negative integers;

each R₁₂ is independently hydrogen, substituted hydrocarbyl, orhydrocarbyl;

R₂₂ and R₃₂ are independently hydrogen substituted hydrocarbyl, orhydrocarbyl;

R₄₂ is hydrogen, hydrocarbyl or substituted hydrocarbyl;

X₁ is

X₂ is alkyl, aminoalkyl, or alkanol;

each X₁₃ is independently hydrogen, hydroxy, alicyclic, amino,aminoalkyl, halogen, alkyl, heteroaryl, boronic acid or aryl;

z is a non-negative number, and

the amine corresponding to Formula 2b comprises at least one allylgroup.

In one embodiment, the crosslinked amine polymer comprises the residueof an amine corresponding to Formula 2b, the crosslinked amine polymeris prepared by radical polymerization of an amine corresponding toFormula 2b, and m and z are independently 0, 1, 2 or 3, and n is 0 or 1.

In one embodiment, the crosslinked amine polymer comprises the residueof an amine corresponding to Formula 2b, the crosslinked amine polymeris prepared by radical polymerization of an amine corresponding toFormula 1, and (i) R₁₂ or R₄₂ independently comprise at least one allylor vinyl moiety, (ii) m is a positive integer and R₂₂ comprises at leastone allyl or vinyl moiety, and/or (iii) n is a positive integer and R₃₂comprises at least one allyl moiety. For example, in one suchembodiment, m and z are independently 0, 1, 2 or 3 and n is 0 or 1. Forexample, in one such embodiment R₁₂ or R₄₂, in combination comprise atleast two allyl or vinyl moieties. By way of further example, in in onesuch embodiment, m is a positive integer and R₁₂, R₂₂ and R₄₂, incombination comprise at least two allyl or vinyl moieties. By way offurther example, in in one such embodiment, n is a positive integer andR₁₂, R₃₂ and R₄₂, in combination comprise at least two allyl or vinylmoieties. By way of further example, in in one such embodiment, m is apositive integer, n is a positive integer and R₁₂, R₂₂, R₃₂ and R₄₂, incombination, comprise at least two allyl or vinyl moieties.

In one embodiment, the crosslinked amine polymer comprises the residueof an amine corresponding to Formula 2b, the crosslinked amine polymeris prepared by radical polymerization of an amine corresponding toFormula 2b, and each R₁₂ is independently hydrogen, aminoalkyl, allyl,or vinyl, R₂₂ and R₃₂ are independently hydrogen, alkyl, aminoalkyl,haloalkyl, alkenyl, alkanol, heteroaryl, alicyclic heterocyclic, oraryl, and R₄₂ is hydrogen or substituted hydrocarbyl. For example, inone such embodiment each R₁₂ is aminoalkyl, allyl or vinyl, R₂₂ and R₃₂are independently hydrogen, alkyl, aminoalkyl, haloalkyl, alkenyl, oralkanol, and R₄₂ is hydrogen or substituted hydrocarbyl. By way offurther example, in one such embodiment each R₁₂ and R₄₂ isindependently hydrogen, alkyl, allyl, vinyl, —(CH₂)_(d)NH₂

or —(CH₂)_(d)N[(CH₂)_(e)NH₂]₂ where d and e are independently 2-4, andR₂₂ and R₃₂ are independently hydrogen or heteroaliphatic.

Exemplary amines and crosslinkers (or the salts thereof, for example thehydrochloric acid, phosphoric acid, sulfuric acid, or hydrobromic acidsalts thereof) for the synthesis of polymers described by Formula 2binclude but are not limited to the ones in Table 3.

TABLE 3 MW Abbreviation Common name IUPAC name (g/mol) DABDA1Diallylbutyldiamine 1,4-Bis(allylamino)butane

241.2  DAEDA1 Diallylethyldiamine 1,2-Bis(allylamino)ethane

213.15 DAEDA2 Diallyldiethylenetriamine 2-(Allylamino)-1-[2-(allylamino)ethylamino]ethane

292.67 DAPDA Diallylpropyldiamine 1,3-Bis(allylamino)propane

227.17 POHDA Diallylamineisopropanol 1,3-Bis(allylamino)-2-propanol

243.17 AAH Allylamine 2-Propen-1-ylamine

93.5 AEAAH Aminoethylallylamine 1-(Allylamino)-2-aminoethane

173.08 BAEAAH Bis(2- aminoethyl)allylamine 1-[N-Allyl(2-aminoethyl)amino]-2- aminoethane

252.61 TAA Triallylamine N,N,N-triallylamine

137.22

In some embodiments, the crosslinked amine polymer is derived from areaction of the resulting polymers that utilize monomers described inany of Formulae 1, 1a, 1b, 1c, 2, 2a and 2b or a linear polymercomprised of a repeat unit described by Formula 3 with externalcrosslinkers or pre-existing polymer functionality that can serve ascrosslinking sites. Formula 3 can be a repeat unit of a copolymer orterpolymer where X₁₅ is either a random, alternating, or blockcopolymer. The repeating unit in Formula 3 can also represent therepeating unit of a polymer that is branched, or hyperbranched, whereinthe primary branch point can be from any atom in the main chain of thepolymer:

wherein

R₁₅, R₁₆ and R₁₇ are independently hydrogen, hydrocarbyl, substitutedhydrocarbyl, hydroxyl, amino, boronic acid or halo;

X₁₅ is

X₅ is hydrocarbyl, substituted hydrocarbyl, oxo (—O—), or amino and z isa non-negative number.

In one embodiment, R₁₅, R₁₆ and R₁₇ are independently hydrogen, aryl, orheteroaryl, X₅ is hydrocarbyl, substituted hydrocarbyl, oxo or amino,and m and z are non-negative integers. In another embodiment, R₁₅, R₁₆and R₁₇ are independently aliphatic or heteroaliphatic, X₅ ishydrocarbyl, substituted hydrocarbyl, oxo (—O—) or amino, and m and zare non-negative integers. In another embodiment, R₁₅, R₁₆ and R₁₇ areindependently unsaturated aliphatic or unsaturated heteroaliphatic, X₅is hydrocarbyl, substituted hydrocarbyl, oxo, or amino, and z is anon-negative integer. In another embodiment, R₁₅, R₁₆ and R₁₇ areindependently alkyl or heteroalkyl, X₅ is hydrocarbyl, substitutedhydrocarbyl, oxo, or amino, and z is a non-negative integer. In anotherembodiment, R₁₅, R₁₆ and R₁₇ are independently alkylamino, aminoalkyl,hydroxyl, amino, boronic acid, halo, haloalkyl, alkanol, or ethereal, X₅is hydrocarbyl, substituted hydrocarbyl, oxo, or amino, and z is anon-negative integer. In another embodiment, R₁₅, R₁₆ and R₁₇ areindependently hydrogen, hydrocarbyl, substituted hydrocarbyl, hydroxyl,amino, boronic acid or halo, X₅ is oxo, amino, alkylamino, ethereal,alkanol, or haloalkyl, and z is a non-negative integer.

Exemplary crosslinking agents that may be used in radical polymerizationreactions include, but are not limited to, one or more multifunctionalcrosslinking agents such as: 1,4-bis(allylamino)butane,1,2-bis(allylamino)ethane,2-(allylamino)-1-[2-(allylamino)ethylamino]ethane,1,3-bis(allylamino)propane, 1,3-bis(allylamino)-2-propanol,triallylamine, diallylamine, divinylbenzene, 1,7-octadiene,1,6-heptadiene, 1,8-nonadiene, 1,9-decadiene, 1,4-divinyloxybutane,1,6-hexamethylenebisacrylamide, ethylene bisacrylamide,N,N′-bis(vinylsulfonylacetyl)ethylene diamine, 1,3-bis(vinylsulfonyl)2-propanol, vinylsulfone, N,N′-methylenebisacrylamide polyvinyl ether,polyallylether, divinylbenzene, 1,4-divinyloxybutane, and combinationsthereof.

Crosslinked polymers derived from the monomers and polymers in formulas1 through 3 may be synthesized either in solution or bulk or indispersed media. Examples of solvents that are suitable for thesynthesis of polymers of the present disclosure include, but are notlimited to water, low boiling alcohols (methanol, ethanol, propanol,butanol), dimethylformamide, dimethylsulfoxide, heptane, chlorobenzene,toluene.

Alternative polymer processes may include, a lone polymerizationreaction, stepwise addition of individual starting material monomers viaa series of reactions, the stepwise addition of blocks of monomers,combinations or any other method of polymerization such as livingpolymerization, direct polymerization, indirect polymerization,condensation, radical, emulsion, precipitation approaches, spray drypolymerization or using some bulk crosslinking reaction methods and sizereduction processes such as grinding, compressing, extrusion. Processescan be carried out as a batch, semi-continuous and continuous processes.For processes in dispersed media, the continuous phase can be non-polarsolvents, such as toluene, benzene, hydrocarbon, halogenated solvents,super critical carbon dioxide. With a direct suspension reaction, watercan be used and salt can be used to tune the properties of thesuspension.

The starting molecules described in formulas 1 through 3 may becopolymerized with one or more other monomers of the invention,oligomers or other polymerizable groups. Such copolymer architecturescan include, but are not limited to, block or block-like polymers, graftcopolymers, and random copolymers. Incorporation of monomers describedby formulas 1 through 3 can range from 1% to 99%. In some embodiments,the incorporation of comonomer is between 20% and 80%.

Non-limiting examples of comonomers which may be used alone or incombination include: styrene, allylamine hydrochloride, substitutedallylamine hydrochloride, substituted styrene, alkyl acrylate,substituted alkyl acrylate, alkyl methacrylate, substituted alkylmethacrylate, acrylonitrile, methacrylonitrile, acrylamide,methacrylamide, N-alkylacrylamide, N-alkylmethacrylamide,N,N-dialkylacrylamide, N,N-dialkylmethacrylamide, isoprene, butadiene,ethylene, vinyl acetate, N-vinyl amide, maleic acid derivatives, vinylether, allyle, methallyl monomers and combinations thereof.Functionalized versions of these monomers may also be used. Additionalspecific monomers or comonomers that may be used in this inventioninclude, but are not limited to, 2-propen-1-ylamine,1-(allylamino)-2-aminoethane,1-[N-allyl(2-aminoethyl)amino]-2-aminoethane, methyl methacrylate, ethylmethacrylate, propyl methacrylate (all isomers), butyl methacrylate (allisomers), 2-ethylhexyl methacrylate, isobornyl methacrylate, methacrylicacid, benzyl methacrylate, phenyl methacrylate, methacrylonitrile,amethylstyrene, methyl acrylate, ethyl acrylate, propyl acrylate (allisomers), butyl acrylate (all isomers), 2-ethylhexyl acrylate, isobornylacrylate, acrylic acid, benzyl acrylate, phenyl acrylate, acrylonitrile,styrene, glycidyl methacrylate, 2-hydroxyethyl methacrylate,hydroxypropyl methacrylate (all isomers), hydroxybutyl methacrylate (allisomers), N,N-dimethylaminoethyl methacrylate, N,N-diethylaminoethylmethacrylate, triethyleneglycol methacrylate, itaconic anhydride,itaconic acid, glycidyl acrylate, 2-hydroxyethyl acrylate, hydroxypropylacrylate (all isomers), hydroxybutyl acrylate (all isomers),N,N-dimethylaminoethyl acrylate, N,N-diethylaminoethyl acrylate,triethyleneglycol acrylate, methacrylamide, N-methylacrylamide,N,N-dimethylacrylamide, N-tert-butylmethacrylamide,N-N-butylmethacrylamide, N-methylolmethacrylamide,N-ethylolmethacrylamide, N-tert-butylacryl amide, N-Nbutylacrylamide,N-methylolacrylamide, N-ethylolacrylamide, 4-acryloylmorpholine, vinylbenzoic acid (all isomers), diethylaminostyrene (all isomers),a-methylvinyl benzoic acid (all isomers), diethylamino a-methylstyrene(all isomers), p-vinylbenzene sulfonic acid, p-vinylbenzene sulfonicsodium salt, trimethoxysilylpropyl methacrylate, triethoxysilylpropylmethacrylate, tributoxysilylpropyl methacrylate,dimethoxymethylsilylpropyl methacrylate, diethoxymethylsilylpropylmethacrylate, dibutoxymethylsilylpropyl methacrylate,diisopropoxymethylsilylpropyl methacrylate, dimethoxysilylpropylmethacrylate, diethoxysilylpropyl methacrylate, dibutoxysilylpropylmethacrylate, diisopropoxysilylpropyl methacrylate,trimethoxysilylpropyl acrylate, triethoxysilylpropyl acrylate,tributoxysilylpropyl acrylate, dimethoxymethylsilylpropyl acrylate,diethoxymethylsilylpropyl acrylate, dibutoxymethylsilylpropyl acrylate,diisopropoxymethylsilylpropyl acrylate, dimethoxysilylpropyl acrylate,diethoxysilylpropyl acrylate, dibutoxysilylpropyl acrylate,diisopropoxysilylpropyl acrylate, maleic anhydride, N-phenylmaleimide,N-butylmaleimide, N-vinylformamide, N-vinyl acetamide, allylamine,methallylamine, allylalcohol, methyl-vinylether, ethylvinylether,butylvinyltether, butadiene, isoprene, chloroprene, ethylene, vinylacetate, and combinations thereof.

Additional modification to the preformed crosslinked polymer can beachieved through the addition of modifiers, including but not limited toamine monomers, additional crosslinkers, and polymers. Modification canbe accomplished through covalent or non-covalent methods. Thesemodifications can be evenly or unevenly dispersed throughout thepreformed polymer material, including modifications biased to thesurface of the preformed crosslinked polymer. Furthermore, modificationscan be made to change the physical properties of the preformedcrosslinked polymer, including but not limited to reactions that occurwith remaining reactive groups such as haloalkyl groups and allyl groupsin the preformed polymer. Reactions and modifications to the preformedcrosslinked polymer can include but are not limited to acid-basereactions, nucleophilic substitution reactions, Michael reactions,non-covalent electrostatic interactions, hydrophobic interactions,physical interactions (crosslinking) and radical reactions.

As described in greater detail in the Examples, polymers in whichcrosslinking and/or entanglement were increased were found to have lowerswelling than those with lower crosslinking and/or entanglement, yetalso had a binding capacity for target ion (e.g., chloride) that was asgreat as or greater than the lower crosslinking and/or entanglementpolymers while binding of interfering ions such as phosphate weresignificantly reduced. The selectivity effect was introduced in twodifferent manners: 1) Overall capacity was sacrificed for chloridespecificity. Crosslinkers that don't include chloride binding sites(e.g. epichlorohydrin) allow for increased crosslinking while overallcapacity is decreased proportional to the amount of crosslinkerincorporated into the polymer. 2) Overall capacity is preserved forchloride specificity: Crosslinkers that include chloride binding sites(e.g. diallylamines) allow for increased crosslinking while overallcapacity is staying the same or is reduced by only a small amount.

The polymers described herein exhibit ion binding properties, generallyproton binding to form the positive charge followed by anion-binding. Inpreferred embodiments, the polymers exhibit chloride binding properties.Ion (e.g., chloride) binding capacity is a measure of the amount of aparticular ion an ion binder can bind in a given solution. For example,binding capacities of ion-binding polymers can be measured in vitro,e.g., in water or in saline solution or in solutions/matrices containingcations and anions representative of gastrointestinal lumen conditions,or in vivo, e.g., from ion (e.g., bicarbonate or citrate) urinaryexcretion, or ex vivo, for example using aspirate liquids, e.g.,chime/gastrointestinal lumen contents obtained from lab animals,patients or volunteers. Measurements can be made in a solutioncontaining only the target ion, or at least no other competing solutesthat compete with target ions for binding to the polymer. In thesecases, a non-interfering buffer would be used (e.g. a solution ofhydrochloric acid, with or without additional sodium chloride).Alternatively, measurements can be made in an interfering buffer thatcontains other competing solutes, e.g., other ions or metabolites thatcompete with target ions for binding to the resin.

In some embodiments the polymer binds hydrochloric acid. For in vivouse, e.g., in treating metabolic acidosis, it is desirable that thepolymer have a high proton and chloride binding capacity. In vitromeasurements of binding capacity do not necessarily translate into invivo binding capacities. Hence, it is useful to define binding capacityin terms of both in vitro and in vivo capacity.

The in vitro chloride binding capacity of the polymers of the inventionin HCl can be greater than about 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 or 15mmol/g. In some embodiments, the in vitro chloride binding capacity ofthe polymers of the invention for target ion is greater than about 5.0mmol/g, preferably greater than about 7.0 mmol/g, even more preferablygreater than about 9.0 mmol/g, and yet even more preferably greater thanabout 10.0 mmol/g. In some embodiments, the chloride binding capacitycan range from about 5.0 mmol/g to about 25 mmol/g, preferably fromabout 7.5 mmol/g to about 20 mmol/g, and even more preferably from about10 mmol/g to about 15 mmol/g. Several techniques are known in the art todetermine the chloride binding capacity.

The in vivo maximum binding capacity (i.e. the maximum amount of [protonand] chloride bound in conditions likely to be encountered in the GItract of a human) can be evaluated by 12-16 h chloride binding in theSimulated Gastric Fluid assay (“SGF”) and is a structural measure forhow well the monomers and crosslinkers were incorporated. The SGF valuesrepresent an experimental confirmation of the theoretical maximumbinding capacity of the polymers and fall in the same range as thecalculated capacity based on the stoichiometry of the startingmaterials.

In order to counterbalance the proton binding, chloride is the anion ofchoice to be bound as its removal has no negative impact on serumbicarbonate. Anions other than chloride, bound to neutralize the protonpositive charge, include phosphate, short chain fatty acids, long chainfatty acids, bile acids or other organic or inorganic anions. Binding ofthese anions, other than chloride, influences overall bicarbonate storesin the intracellular and extracellular compartments.

The selectivity of the polymer for binding chloride can be evaluated invitro using conditions that mimic various conditions, anions and anionconcentrations encountered in the GI lumen. The chloride binding can becompared versus phosphate alone (e.g. SIB [Simulated Intestinal Buffer];or versus a range of anions found in the GI tract (e.g., SOB).

In some embodiments, the chloride binding in the SIB assay after onehours exposure of the polymer to the test buffer at 37° C. is greaterthan about 2.0 mmol per gram of polymer, preferably greater than about2.5 mmol/g of polymer, more preferably greater than about 3.0 mmol/g ofpolymer, even more preferably greater than about 3.5 mmol/g of polymerand most preferably greater than about 4.0 mmol/g of polymer.

In some embodiments, the chloride binding in the SOB assay after twohours exposure of the polymer to the test buffer at 37° C. is greaterthan about 1.0 mmol per gram of polymer, preferably greater than about2.0 mmol/g of polymer, more preferably greater than about 3.0 mmol/g ofpolymer, even more preferably greater than about 3.5 mmol/g of polymerand most preferably greater than about 4.0 mmol/g of polymer.

In some embodiments, the chloride binding in this SOB assay after fortyeight hours exposure of the polymer to the test buffer at 37° C. isgreater than about 0.5 mmol per gram of polymer, preferably greater thanabout 1 mmol/g of polymer, more preferably greater than about 2.0 mmol/gof polymer, even more preferably greater than about 3.0 mmol/g ofpolymer and most preferably greater than about 4.0 mmol/g of polymer.The chloride binding in SOB after 48 hours exposure at 37° C. is onemeasure of the ability of a polymer to retain chloride as it passesthrough the GI tract.

Another way of measuring (proton and) chloride retention is to firstexpose the polymer to SOB, to isolate the polymer and then to expose thepolymer to conditions that are typical of the colon lumen, for exampleusing the “chloride retention assay” (CRA) buffer. In some embodiments,the amount of chloride remaining bound to the polymer after two hoursexposure to SOB at 37° C. and then 48 hours exposure to CRA at 37° C. isgreater than about 0.2 mmol per gram of polymer, preferably greater thanabout 0.5 mmol/g of polymer, more preferably greater than about 1.0mmol/g of polymer, even more preferably greater than about 2.0 mmol/g ofpolymer and most preferably greater than about 3.0 mmol/g of polymer.

In some embodiments, the in vivo binding performance of polymers of thepresent disclosure can be evaluated by measuring the change in urineacid levels after administration to an animal, including a human, withnormal renal function. The removal of additional HCl (or HCl equivalent)from the body by the action of the administered polymer, given enoughtime to reach metabolic equilibrium, is reflected in changes in urinebicarbonate, titratable acid, citrate or other indicators of urinaryacid excretion.

In order to bind protons, the amine constituents of the polymers can beprimary, secondary or tertiary amines, but not quaternary amines.Quaternary amines remain substantially charged at all physiologicalconditions and therefore do not bind a proton before an anion is bound.The percentage of quaternary amines can be measured in a number of ways,including titration and back titration approaches. Another simple butaccurate method is to compare anion (e.g. chloride) binding at low andhigh pH. While chloride binding at low pH (e.g. the SGF bufferconditions; pH 1.2) does not distinguish quaternary amines from otheramines, chloride binding assay at high pH (e.g. QAA buffer conditions;pH 11.5) does. At this high pH, primary, secondary and tertiary aminesare not substantially protonated and do not contribute to chloridebinding. Therefore any binding observed under these conditions can beattributed to the presence of permanently charged quaternary amines. Acomparison of chloride binding at low pH (e.g. SGF conditions) versushigh pH (e.g. QAA conditions) is a measure of the degree ofquaternization and by extension is a measure of the amount of protonbound along with the chloride. The polymers of the current disclosurecontain no more than 40%, 30%, 20%, 10%, most preferably 5% quaternaryamines.

The swelling ratio of the polymers of the present disclosure representan experimental confirmation of the degree of crosslinking and byextension the relative pore sizes of the polymers and accessibility toanions larger than (or with a hydration ratio larger than) chloride. Insome embodiments the swelling is measured in deionized water and isexpressed in terms of grams of water per gram of dry polymer. Thepolymers of the current disclosure have a swelling ratio in deionizedwater of ≤5 g/g, ≤4 g/g, ≤3 g/g, ≤2 g/g or ≤1 g/g.

The ability of polymer to retain chloride (and not release it, allowingexchange with other anions) as it passes through different conditionsexperienced in the GI lumen is an important characteristic that islikely to be a predictor of relative in vivo efficacy. The chlorideretention assay (CRA) can be used to evaluate chloride retention. An SOB(Simulated Intestinal Organic/Inorganic Buffer) screen is firstperformed to allow chloride and other anions to bind to the polymers,the polymers are isolated and exposed to conditions mimicking the colonlumen (e.g. retention assay matrix) for 40 hours. The polymers are againisolated and the anions remaining bound to the polymer are eluted insodium hydroxide and measured. The polymers of the current disclosureretain more than 50%, 60%, 70%, 80% or most preferably more than 90% ofchloride bound after being submitted to the chloride retention assay asdescribed.

Using heterogeneous polymerization processes, polymer particles areobtained as spherical beads, whose diameter is controlled in the 5 to1000 microns range, preferably 10 to 500 microns and most preferred40-180 microns.

In general, a pharmaceutical composition of the present disclosurecomprises a proton-binding, crosslinked amine polymer described herein.Preferably, the pharmaceutical composition comprising the crosslinkedamine polymer is formulated for oral administration. The form of thepharmaceutical in which the polymer is administered includes powders,tablets, pills, lozenges, sachets, cachets, elixirs, suspensions,syrups, soft or hard gelatin capsules, and the like. In one embodiment,the pharmaceutical composition comprises only the crosslinked aminepolymer. Alternatively, the pharmaceutical composition may comprise acarrier, a diluent, or excipient in addition to the crosslinked aminepolymer. Examples of carriers, excipients, and diluents that may be usedin these formulations as well as others, include foods, drinks, lactose,dextrose, sucrose, sorbitol, mannitol, starches, gum acacia, alginates,tragacanth, gelatin, calcium silicate, microcrystalline cellulose,polyvinylpyrrolidone, cellulose, methyl cellulose,methylhydroxybenzoates, propylhydroxybenzoates, propylhydroxybenzoates,and talc. Pharmaceutical excipients useful in the pharmaceuticalcompositions further include a binder, such as microcrystallinecellulose, colloidal silica and combinations thereof (Prosolv 90),carbopol, providone and xanthan gum; a flavoring agent, such as sucrose,mannitol, xylitol, maltodextrin, fructose, or sorbitol; a lubricant,such as magnesium stearate, stearic acid, sodium stearyl fumurate andvegetable based fatty acids; and, optionally, a disintegrant, such ascroscarmellose sodium, gellan gum, low-substituted hydroxypropyl etherof cellulose, sodium starch glycolate. Other additives may includeplasticizers, pigments, talc, and the like. Such additives and othersuitable ingredients are well-known in the art; see, e.g., Gennaro A R(ed), Remington's Pharmaceutical Sciences, 20th Edition.

In one embodiment, pharmaceutical compositions comprising a crosslinkedamine polymer of the present disclosure contain relatively low amountsof sodium. For example, in one such embodiment the pharmaceuticalcomposition comprises less than 1 g of sodium per dose. By way offurther example, in one such embodiment the pharmaceutical compositioncomprises less than 0.5 g sodium per dose. By way of further example, inone such embodiment the pharmaceutical composition comprises less than0.1 g sodium per dose. By way of further example, in one such embodimentthe pharmaceutical composition is sodium-free.

In one embodiment, the daily dose of the new chronic metabolic acidosistreatment is compliance enhancing (approximately 5 g or less per day)and achieves a clinically significant and sustained increase of serumbicarbonate of approximately 3 mEq/L at these daily doses. Thenon-absorbed nature of the polymer and the lack of sodium load and/orintroduction of other deleterious ions for such an oral drug enable forthe first time a safe, chronic treatment of metabolic acidosis withoutworsening blood pressure/hypertension and/or without causing increasedfluid retention and fluid overload. Another benefit is further slowingof the progression of kidney disease and time to onset of lifelong renalreplacement therapy (End Stage Renal Disease “ESRD” including 3 times aweek dialysis) or need for kidney transplants. Both are associated withsignificant mortality, low quality of life and significant burden tohealthcare systems around the world. In the United States alone,approximately 20% of the 400,000 ESRD patients die and 100,000 newpatients start dialysis every year.

In one embodiment, the pharmaceutical composition comprises asodium-free, non-absorbed, cross-linked, amine polymer for treatment ofmetabolic acidosis that increases serum bicarbonate and normalizes bloodpH in a mammal by binding HCl. One preferred embodiment includes thepolymer binding H⁺ in the stomach/upper GI tract followed by binding Cl⁻in sufficient amounts to cause a clinically meaningful increase of serumbicarbonate of at least 1.6 mEq/L, more preferred of at least 2 mEq/Land most preferred of equal or greater 3 mEq/L. The amount of HClbinding is determined by the polymer's capacity (targeted range of HClbinding capacity of 5-20 mEq of HCl per 1 g of polymer) and selectivity.In the stomach, free amine becomes protonated by binding H⁺. Thepositive charge formed in situ on the polymer is then available to bindCl⁻; by controlling access of binding sites through crosslinking (sizeexclusion, mesh size) and chemical moieties (to repel larger, organicions (such as acetate, propionate and butyrate or other short chainfatty acids commonly present in the colon), phosphate, bile and fattyacids through tailored hydrophilicity/hydrophobicity), anions other thanchloride are bound to a lesser degree if at all. By tailoring the beadcrosslinking and the chemical nature of the amine binding sites,chloride can be bound tightly to ensure that it is not released in thelower GI tract. HCl is removed from the body through regular bowlmovement/feces, resulting in net HCl binding. In another embodiment, thepolymer comes pre-formed with some quaternized/protonated amine groupsand chloride binding is achieved through ion exchange with citrate orcarbonate where up to 90% of cationic binding sites on the polymer comepre-loaded with citrate and/or carbonate as the counter-ion.

In one embodiment, a key feature of the sodium-free, non-absorbed, aminepolymer for treatment of metabolic acidosis that increases serumbicarbonate and normalizes blood pH in a mammal is that it does notincrease blood pressure or worsen hypertension which is of particularconcern in diabetic kidney disease patients. An additional benefit ofnot introducing sodium is the lack of related increase in fluidretention causing fluid overload which is of particular concern in heartfailure patients. The polymer's ability to safely and efficaciouslytreat metabolic acidosis without introducing deleterious counter-ionsallows for slowing of progression of kidney disease which is ofparticular concern in chronic kidney disease patients who are not ondialysis yet. The onset of dialysis could be delayed by at least 3, 6, 9or 12 months.

In yet another embodiment of the sodium-free, non-absorbed, aminepolymer for treatment of metabolic acidosis, the polymer is acrosslinked bead with a preferred particle size range that is (i) largeenough to avoid passive or active absorption through the GI tract and(ii) small enough to not cause grittiness or unpleasant mouth feel wheningested as a powder, sachet and/or chewable tablet/dosage form with anaverage particle size of 40-180 microns. Preferably, the desiredparticle size morphology is accomplished through a heterogeneouspolymerization reaction such as a suspension or emulsion polymerization.To minimize GI side effects in patients that are often related to alarge volume polymer gel moving through the GI tract, a low swellingratio of the polymer is preferred (0.5-5 times its own weight in water).In yet another embodiment, the polymer carries a molecular entitypermanently/covalently and/or temporarily attached to a polymer or onits own that blocks the Cl⁻/HCO₃ ⁻ exchanger (antiporter) in the colonand intestine. The net effect of blocking the antiporter is to reduceuptake of Cl⁻ from the intestinal lumen and related exchange forbicarbonate from the serum, thus effectively increasing serumbicarbonate.

In one embodiment, the crosslinked amine polymer may be co-administeredwith other active pharmaceutical agents depending on the condition beingtreated. This co-administration may include simultaneous administrationof the two agents in the same dosage form, simultaneous administrationin separate dosage forms, and separate administration. For example, forthe treatment of metabolic acidosis, the crosslinked amine polymer maybe co-administered with common treatments that are required to treatunderlying co-morbidities including but not limited to hypertension,diabetes, obesity, heart failure and complications of Chronic KidneyDisease. These medications and the crosslinked amine polymer can beformulated together in the same dosage form and administeredsimultaneously as long as they do not display any clinically significantdrug-drug-interactions. Alternatively, these treatments and thecrosslinked amine polymer may be separately and sequentiallyadministered with the administration of one being followed by theadministration of the other.

In further embodiments, numbered 1-104 below, the present includes

Embodiment 1

A pharmaceutical composition comprising a proton-binding, crosslinkedamine polymer comprising the residue of an amine corresponding toFormula 1:

wherein R₁, R₂ and R₃ are independently hydrogen, hydrocarbyl, orsubstituted hydrocarbyl provided, however, at least one of R₁, R₂ and R₃is other than hydrogen, and the crosslinked amine polymer has (i) anequilibrium proton binding capacity of at least 5 mmol/g and a chlorideion binding capacity of at least 5 mmol/g in an aqueous simulatedgastric fluid buffer (“SGF”) containing 35 mM NaCl and 63 mM HCl at pH1.2 and 37° C., and (ii) an equilibrium swelling ratio in deionizedwater of about 2 or less.

Embodiment 2

A pharmaceutical composition comprising a proton-binding, crosslinkedamine polymer comprising the residue of an amine corresponding toFormula 1:

wherein R₁, R₂ and R₃ are independently hydrogen, hydrocarbyl,substituted hydrocarbyl provided, however, at least one of R₁, R₂ and R₃is other than hydrogen, the crosslinked amine polymer has an equilibriumswelling ratio in deionized water of about or less, and the crosslinkedamine polymer binds a molar ratio of chloride ions to interfering ionsof at least 0.35:1, respectively, in an interfering ion buffer at 37° C.wherein (i) the interfering ions are phosphate ions and the interferingion buffer is a buffered solution at pH 5.5 of 36 mM chloride and 20 mMphosphate or (ii) the interfering ions are phosphate, citrate andtaurocholate ions (combined amount) and the interfering ion buffer is abuffered solution at pH 6.2 including 36 mM chloride, 7 mM phosphate,1.5 mM citrate, and 5 mM taurocholate.

Embodiment 3

The pharmaceutical composition of embodiment 1 wherein the crosslinkedamine polymer has an equilibrium chloride binding capacity of at least7.5 mmol/g in an aqueous simulated gastric fluid buffer (“SGF”)containing 35 mM NaCl and 63 mM HCl at pH 1.2 and 37° C.

Embodiment 4

The pharmaceutical composition of embodiment 1 wherein the crosslinkedamine polymer has an equilibrium chloride binding capacity of at least10 mmol/g in an aqueous simulated gastric fluid buffer (“SGF”)containing 35 mM NaCl and 63 mM HCl at pH 1.2 and 37° C.

Embodiment 5

The pharmaceutical composition of embodiment 2 wherein the crosslinkedamine polymer binds more chloride than any one of the interfering anionsin the interfering ion buffer, the interfering ions are phosphate,citrate and taurocholate ions and the interfering ion buffer is abuffered solution at pH 6.2 including 36 mM chloride, 7 mM phosphate,1.5 mM citrate, and 5 mM taurocholate.

Embodiment 6

The pharmaceutical composition of embodiment 2 wherein at least 66% ofthe combined amount of chloride and interfering ions bound by thecrosslinked amine polymer in the interfering ion buffer are chlorideanions, the interfering ions are phosphate, citrate and taurocholate,and the interfering ion buffer is a buffered solution at pH 6.2including 36 mM chloride, 7 mM phosphate, 1.5 mM citrate, and 5 mMtaurocholate.

Embodiment 7

The pharmaceutical composition of embodiment 2 wherein 90% or more ofthe combined amount of chloride and interfering ions bound by thecrosslinked amine polymer in the interfering ion buffer are chlorideanions, the interfering ions are phosphate, citrate and taurocholate,and the interfering ion buffer is a buffered solution at pH 6.2including 36 mM chloride, 7 mM phosphate, 1.5 mM citrate, and 5 mMtaurocholate.

Embodiment 8

The pharmaceutical composition of embodiment 2 wherein the crosslinkedamine polymer has an equilibrium swelling ratio in deionized water ofabout 4 or less.

Embodiment 9

The pharmaceutical composition of embodiment 2 wherein the crosslinkedamine polymer has an equilibrium swelling ratio in deionized water ofabout 3 or less.

Embodiment 10

The pharmaceutical composition of embodiment 2 wherein the crosslinkedamine polymer has an equilibrium swelling ratio in deionized water ofabout 2 or less.

Embodiment 11

The pharmaceutical composition of any preceding embodiment wherein R₁,R₂ and R₃ are independently hydrogen, alkyl, alkenyl, allyl, vinyl,aryl, aminoalkyl, alkanol, haloalkyl, hydroxyalkyl, ethereal, heteroarylor heterocyclic provided, however, each of R₁, R₂ and R₃ is nothydrogen.

Embodiment 12

The pharmaceutical composition of any preceding embodiment wherein R₁,R₂ and R₃ are independently hydrogen, aliphatic or heteroaliphaticprovided, however, at least one of R₁, R₂ and R₃ is other than hydrogen.

Embodiment 13

The pharmaceutical composition of any preceding embodiment wherein thecrosslinked amine polymer is prepared by substitution polymerization ofthe amine with a polyfunctional crosslinker, optionally also comprisingamine moieties.

Embodiment 14

The pharmaceutical composition of any of embodiments 1-12 wherein thecrosslinked amine polymer comprises the residue of an aminecorresponding to Formula 1a and the crosslinked amine polymer isprepared by radical polymerization of an amine corresponding to Formula1a:

wherein R₄ and R₅ are independently hydrogen, hydrocarbyl, orsubstituted hydrocarbyl.

Embodiment 15

The pharmaceutical composition of embodiment 14 wherein R₄ and R₅ areindependently hydrogen, alkyl, alkenyl, allyl, vinyl, aryl, aminoalkyl,alkanol, haloalkyl, hydroxyalkyl, ethereal, heteroaryl or heterocyclic.

Embodiment 16

The pharmaceutical composition of embodiment 14 wherein R₄ and R₅ areindependently hydrogen, aliphatic or heteroaliphatic.

Embodiment 17

The pharmaceutical composition of any of embodiments 1-12 wherein thecrosslinked amine polymer comprises the residue of an aminecorresponding to Formula 1b and the crosslinked amine polymer isprepared by substitution polymerization of the amine corresponding toFormula 1b with a polyfunctional crosslinker:

wherein R₄ and R₅ are independently hydrogen, hydrocarbyl, orsubstituted hydrocarbyl, R₆ is aliphatic and R₆₁ and R₆₂ areindependently hydrogen, aliphatic, or heteroaliphatic.

Embodiment 18

The pharmaceutical composition of embodiment 17 wherein R₄ and R₅ areindependently hydrogen, saturated hydrocarbon, unsaturated aliphatic,aryl, heteroaryl, heteroalkyl, or unsaturated heteroaliphatic.

Embodiment 19

The pharmaceutical composition of embodiment 17 wherein R₄ and R₅ areindependently hydrogen, alkyl, alkenyl, allyl, vinyl, aryl, aminoalkyl,alkanol, haloalkyl, hydroxyalkyl, ethereal, heteroaryl or heterocyclic.

Embodiment 20

The pharmaceutical composition of embodiment 17 wherein R₄ and R₅ areindependently hydrogen, allyl, or aminoalkyl.

Embodiment 21

The pharmaceutical composition of any preceding embodiment wherein thecrosslinked amine polymer comprises the residue of an aminecorresponding to Formula 1c:

wherein R₇ is hydrogen, aliphatic or heteroaliphatic and R₈ is aliphaticor heteroaliphatic.

Embodiment 22

The pharmaceutical composition of any of embodiments 1-12 wherein thecrosslinked amine polymer comprises the residue of an aminecorresponding to Formula 2:

wherein

m and n are independently non-negative integers;

R₁₀, R₂₀, R₃₀, and R₄₀ are independently hydrogen, hydrocarbyl, orsubstituted hydrocarbyl;

X₁ is

X₂ is hydrocarbyl or substituted hydrocarbyl;

each X₁₁ is independently hydrogen, hydrocarbyl, substitutedhydrocarbyl, hydroxy, or amino; and

z is a non-negative number.

Embodiment 23

The pharmaceutical composition of embodiment 22 wherein R₁₀, R₂₀, R₃₀,and R₄₀ are independently hydrogen, aliphatic, aryl, heteroaliphatic, orheteroaryl, m and z are independently 0-3 and n is 0 or 1.

Embodiment 24

The pharmaceutical composition of embodiment 22 or 23 wherein X₂ isaliphatic or heteroaliphatic.

Embodiment 25

The pharmaceutical composition of embodiment 22, 23 or 24 wherein m is1-3 and X₁₁ is hydrogen, aliphatic or heteroaliphatic.

Embodiment 26

The pharmaceutical composition of any of embodiments 1-12 wherein thecrosslinked amine polymer comprises the residue of an aminecorresponding to Formula 2a:

wherein

m and n are independently non-negative integers;

each R₁₁ is independently hydrogen, hydrocarbyl, heteroaliphatic, orheteroaryl;

R₂₁ and R₃₁, are independently hydrogen or heteroaliphatic;

R₄₁ is hydrogen, substituted hydrocarbyl, or hydrocarbyl;

X₁ is

X₂ is alkyl or substituted hydrocarbyl;

each X₁₂ is independently hydrogen, hydroxy, amino, aminoalkyl, boronicacid or halo; and

z is a non-negative number.

Embodiment 27

The pharmaceutical composition of embodiment 26 wherein m and z areindependently 0-3 and n is 0 or 1.

Embodiment 28

The pharmaceutical composition of embodiment 26 or 27 wherein R₁₁ isindependently hydrogen, aliphatic, aminoalkyl, haloalkyl, or heteroaryl,R₂₁ and R₃₁ are independently hydrogen or heteroaliphatic and R₄₁ ishydrogen, aliphatic, aryl, heteroaliphatic, or heteroaryl.

Embodiment 29

The pharmaceutical composition of embodiment 26 or 27 wherein each R₁₁is hydrogen, aliphatic, aminoalkyl, or haloalkyl, R₂₁ and R₃₁ arehydrogen or aminoalkyl, and R₄₁ is hydrogen, aliphatic, orheteroaliphatic.

Embodiment 30

The pharmaceutical composition of any of embodiments 1-12 wherein thecrosslinked amine polymer comprises the residue of an aminecorresponding to Formula 2b:

wherein

m and n are independently non-negative integers;

each R₁₂ is independently hydrogen, substituted hydrocarbyl, orhydrocarbyl;

R₂₂ and R₃₂ are independently hydrogen substituted hydrocarbyl, orhydrocarbyl;

R₄₂ is hydrogen, hydrocarbyl or substituted hydrocarbyl;

X₁ is

X₂ is alkyl, aminoalkyl, or alkanol;

each X₁₃ is independently hydrogen, hydroxy, alicyclic, amino,aminoalkyl, halogen, alkyl, heteroaryl, boronic acid or aryl;

z is a non-negative number; and

the amine corresponding to Formula 2b comprises at least one allylgroup.

Embodiment 31

The pharmaceutical composition of embodiment 30 wherein m and z areindependently 0-3 and n is 0 or 1.

Embodiment 32

The pharmaceutical composition of embodiment 30 or 31 wherein R₁₂ or R₄₂independently comprise at least one allyl or vinyl moiety.

Embodiment 33

The pharmaceutical composition of embodiment 30 or 31 wherein (i) m is apositive integer and R₁₂, R₂₂ and R₄₂, in combination comprise at leasttwo allyl or vinyl moieties or (ii) n is a positive integer and R₁₂, R₃₂and R₄₂, in combination, comprise at least two allyl or vinyl moieties.

Embodiment 34

The pharmaceutical composition of embodiment 30 or 31 wherein thecrosslinked amine polymer comprises the residue of an amine appearing inTable 1.

Embodiment 35

The pharmaceutical composition of embodiment 30, 31 or 34 wherein thecrosslinked amine polymer is crosslinked with a crosslinking agentappearing in Table 2.

Embodiment 36

The pharmaceutical composition of any preceding embodiment wherein thecrosslinked amine polymer comprises a repeat unit corresponding toFormula 3:

wherein

R₁₅, R₁₆ and R₁₇ are independently hydrogen, hydrocarbyl, substitutedhydrocarbyl, hydroxyl, amino, boronic acid or halo;

X₁₅ is

X₅ is hydrocarbyl, substituted hydrocarbyl, oxo (—O—), or amino; and

z is a non-negative number.

Embodiment 37

The pharmaceutical composition of embodiment 36 wherein R₁₅, R₁₆ and R₁₇are independently aliphatic or heteroaliphatic.

Embodiment 38

The pharmaceutical composition of embodiment 36 or 37 wherein X₅ is oxo,amino, alkylamino, ethereal, alkanol, or haloalkyl.

Embodiment 39

The pharmaceutical composition of any of embodiments 1-12 wherein thecrosslinked amine polymer is prepared by (i) substitution polymerizationof polyfunctional reagents at least one of which comprises aminemoieties, (2) radical polymerization of a monomer comprising at leastone amine moiety or nitrogen containing moiety, or (3) crosslinking ofan amine-containing intermediate with a crosslinking agent, optionallycontaining amine moieties.

Embodiment 40

The pharmaceutical composition of embodiment 39 wherein the crosslinkedamine polymer is a crosslinked homopolymer or a crosslinked copolymer.

Embodiment 41

The pharmaceutical composition of embodiment 39 wherein the crosslinkedamine polymer comprises free amine moieties, separated by the same orvarying lengths of repeating linker units.

Embodiment 42

The pharmaceutical composition of embodiment 39 wherein the crosslinkedamine polymer is prepared by polymerizing an amine-containing monomerwith a crosslinking agent in a substitution polymerization reaction.

Embodiment 43

The pharmaceutical composition of embodiment 42 wherein theamine-containing monomer is a linear amine possessing at least tworeactive amine moieties to participate in the substitutionpolymerization reaction.

Embodiment 44

The pharmaceutical composition of embodiment 42 or 43 wherein theamine-containing monomer is 1,3-Bis[bis(2-aminoethyl)amino]propane,3-Amino-1-{[2-(bis{2-[bis(3-aminopropyl)amino]ethyl}amino)ethyl](3-aminopropyl)amino}propane,2-[Bis(2-aminoethyl)amino]ethanamine, Tris(3-aminopropyl)amine,1,4-Bis[bis(3-aminopropyl)amino]butane, 1,2-Ethanediamine,2-Amino-1-(2-aminoethylamino)ethane, 1,2-Bis(2-aminoethylamino)ethane,1,3-Propanediamine, 3,3′-Diaminodipropylamine,2,2-dimethyl-1,3-propanediamine, 2-methyl-1,3-propanediamine,N,N′-dimethyl-1,3-propanediamine, N-methyl-1,3-diaminopropane,3,3′-diamino-N-methyldipropylamine, 1,3-diaminopentane,1,2-diamino-2-methylpropane, 2-methyl-1,5-diaminopentane,1,2-diaminopropane, 1,10-diaminodecane, 1,8-diaminooctane,1,9-diaminooctane, 1,7-diaminoheptane, 1,6-diaminohexane,1,5-diaminopentane, 3-bromopropylamine hydrobromide,N,2-dimethyl-1,3-propanediamine, N-isopropyl-1,3-diaminopropane,N,N′-bis(2-aminoethyl)-1,3-propanediamine,N,N′-bis(3-aminopropyl)ethylenediamine,N,N′-bis(3-aminopropyl)-1,4-butanediamine tetrahydrochloride,1,3-diamino-2-propanol, N-ethylethylenediamine,2,2′-diamino-N-methyldiethylamine, N,N′-diethylethylenediamine,N-isopropylethylenediamine, N-methylethylenediamine,N,N′-di-tert-butylethylenediamine, N,N′-diisopropylethylenediamine,N,N′-dimethylethylenediamine, N-butylethylenediamine,2-(2-aminoethylamino)ethanol, 1,4,7,10,13,16-hexaazacyclooctadecane,1,4,7,10-tetraazacyclododecane, 1,4,7-triazacyclononane,N,N′-bis(2-hydroxyethyl)ethylenediamine, piperazine,bis(hexamethylene)triamine, N-(3-hydroxypropyl)ethylenediamine,N-(2-Aminoethyl)piperazine, 2-Methylpiperazine, Homopiperazine,1,4,8,11-Tetraazacyclotetradecane, 1,4,8,12-Tetraazacyclopentadecane,2-(Aminomethyl)piperidine, or 3-(Methylamino)pyrrolidino.

Embodiment 45

The pharmaceutical composition of any of embodiments 39, 41, 43 and 44wherein the crosslinking agent is selected from the group consisting ofdihaloalkanes, haloalkyloxiranes, alkyloxirane sulfonates,di(haloalkyl)amines, tri(haloalkyl) amines, diepoxides, triepoxides,tetraepoxides, bis (halomethyl)benzenes, tri(halomethyl)benzenes,tetra(halomethyl)benzenes, epihalohydrins such as epichlorohydrin andepibromohydrin poly(epichlorohydrin), (iodomethyl)oxirane, glycidyltosylate, glycidyl 3-nitrobenzenesulfonate, 4-tosyloxy-1,2-epoxybutane,bromo-1,2-epoxybutane, 1,2-dibromoethane, 1,3-dichloropropane,1,2-dichloroethane, I-bromo-2-chloroethane, 1,3-dibromopropane,bis(2-chloroethyl)amine, tris(2-chloroethyl)amine, andbis(2-chloroethyl)methylamine, 1,3-butadiene diepoxide, 1,5-hexadienediepoxide, diglycidyl ether, 1,2,7,8-diepoxyoctane,1,2,9,10-diepoxydecane, ethylene glycol diglycidyl ether, propyleneglycol diglycidyl ether, 1,4-butanediol diglycidyl ether, 1,2ethanedioldiglycidyl ether, glycerol diglycidyl ether, 1,3-diglycidylglyceryl ether, N,N-diglycidylaniline, neopentyl glycol diglycidylether, diethylene glycol diglycidyl ether, 1,4-bis(glycidyloxy)benzene,resorcinol digylcidyl ether, 1,6-hexanediol diglycidyl ether,trimethylolpropane diglycidyl ether, 1,4-cyclohexanedimethanoldiglycidyl ether, 1,3-bis-(2,3-epoxypropyloxy)-2-(2,3-dihydroxypropyloxy)propane, 1,2-cyclohexanedicarboxylic acid diglycidyl ester,2,2′-bis(glycidyloxy) diphenylmethane, bisphenol F diglycidyl ether,1,4-bis(2′,3′epoxypropyl)perfluoro-n-butane, 2,6-di(oxiran-2-ylmethyl)-1,2,3,5,6,7-hexahydropyrrolo[3,4-f]isoindol-1,3,5,7-tetraone,bisphenol A diglycidyl ether, ethyl5-hydroxy-6,8-di(oxiran-2-ylmethyl)-4-oxo-4-h-chromene-2-carboxylate,bis[4-(2,3-epoxy-propylthio )phenyl]-sulfide, 1,3-bis(3-glycidoxypropyl)tetramethyldisiloxane, 9,9-bis[4-(glycidyloxy)phenyl]fluorine,triepoxyisocyanurate, glycerol triglycidyl ether,N,N-diglycidyl-4-glycidyloxyaniline, isocyanuric acid(S,S,S)-triglycidyl ester, isocyanuric acid (R,R,R)-triglycidyl ester,triglycidyl isocyanurate, trimethylolpropane triglycidyl ether, glycerolpropoxylate triglycidyl ether, triphenylolmethane triglycidyl ether,3,7,14-tris[[3-(epoxypropoxy)propyl]dimethylsilyloxy]-1,3,5,7,9,11,14-heptacyclopentyltricyclo[7,3,3,15, 11]heptasiloxane, 4,4′ methylenebis(N,N-diglycidylaniline),bis(halomethyl)benzene, bis(halomethyl)biphenyl andbis(halomethyl)naphthalene, toluene diisocyanate, acrylol chloride,methyl acrylate, ethylene bisacrylamide, pyrometallic dianhydride,succinyl dichloride, dimethylsuccinate,3-chloro-1-(3-chloropropylamino-2-propanol,1,2-bis(3-chloropropylamino)ethane, Bis(3-chloropropyl)amine,1,3-Dichloro-2-propanol, 1,3-Dichloropropane, 1-chloro-2,3-epoxypropane,tris[(2-oxiranyl)methyl]amine, and combinations thereof.

Embodiment 46

The pharmaceutical composition of embodiment 39 wherein the preparationof the crosslinked amine polymer comprises radical polymerization of anamine monomer comprising at least one amine moiety or nitrogencontaining moiety.

Embodiment 47

The pharmaceutical composition of any preceding embodiment wherein thecrosslinked amine polymer has an equilibrium swelling ratio in deionizedwater of about 1.5 or less.

Embodiment 48

The pharmaceutical composition of any preceding embodiment wherein thecrosslinked amine polymer has an equilibrium swelling ratio in deionizedwater of about 1 or less.

Embodiment 49

The pharmaceutical composition of any preceding embodiment wherein thecrosslinked amine polymer has a chloride ion to phosphate ion bindingmolar ratio of at least 0.5:1, respectively, in an aqueous simulatedsmall intestine inorganic buffer (“SIB”) containing 36 mM NaCl, 20 mMNaH₂PO₄, and 50 mM 2-(N-morpholino)ethanesulfonic acid (MES) buffered topH 5.5 and at 37° C.

Embodiment 50

The pharmaceutical composition of any preceding embodiment wherein thecrosslinked amine polymer has a chloride ion to phosphate ion bindingmolar ratio of at least 1:1, respectively, in an aqueous simulated smallintestine inorganic buffer (“SIB”) containing 36 mM NaCl, 20 mM NaH₂PO₄,and 50 mM 2-(N-morpholino)ethanesulfonic acid (MES) buffered to pH 5.5and at 37° C.

Embodiment 51

The pharmaceutical composition of any preceding embodiment wherein thecrosslinked amine polymer has a chloride ion to phosphate ion bindingmolar ratio of at least 2:1, respectively, in an aqueous simulated smallintestine inorganic buffer (“SIB”) containing 36 mM NaCl, 20 mM NaH₂PO₄,and 50 mM 2-(N-morpholino)ethanesulfonic acid (MES) buffered to pH 5.5and at 37° C.

Embodiment 52

The pharmaceutical composition of any preceding embodiment wherein thecrosslinked amine polymer has a proton binding capacity of at least 10mmol/g and a chloride ion binding capacity of at least 10 mmol/g in anaqueous simulated gastric fluid buffer (“SGF”) containing 35 mM NaCl and63 mM HCl at pH 1.2 and 37° C.

Embodiment 53

The pharmaceutical composition of any preceding embodiment wherein thecrosslinked amine polymer has an equilibrium proton binding capacity ofat least 12 mmol/g and a chloride ion binding capacity of at least 12mmol/g in an aqueous simulated gastric fluid buffer (“SGF”) containing35 mM NaCl and 63 mM HCl at pH 1.2 and 37° C.

Embodiment 54

The pharmaceutical composition of any preceding embodiment wherein thecrosslinked amine polymer has an equilibrium proton binding capacity ofat least 14 mmol/g and a chloride ion binding capacity of at least 14mmol/g in an aqueous simulated gastric fluid buffer (“SGF”) containing35 mM NaCl and 63 mM HCl at pH 1.2 and 37° C.

Embodiment 55

The pharmaceutical composition of any preceding embodiment wherein thecrosslinked amine polymer has a chloride binding capacity of at least 1mmol/g in an aqueous simulated small intestine organic and inorganicbuffer (“SOB”) containing 50 mM 2-(N-morpholino)ethanesulfonic acid(MES), 50 mM sodium acetate, 36 mM sodium chloride, 7 mM sodiumphosphate, 1.5 mM sodium citrate, 30 mM oleic acid and 5 mM sodiumtaurocholate, buffered to pH 6.2 and at 37° C.

Embodiment 56

The pharmaceutical composition of any preceding embodiment wherein thecrosslinked amine polymer has a chloride binding capacity of at least 2mmol/g in an aqueous simulated small intestine organic and inorganicbuffer (“SOB”) containing 50 mM 2-(N-morpholino)ethanesulfonic acid(MES), 50 mM sodium acetate, 36 mM sodium chloride, 7 mM sodiumphosphate, 1.5 mM sodium citrate, 30 mM oleic acid and 5 mM sodiumtaurocholate, buffered to pH 6.2 and at 37° C.

Embodiment 57

The pharmaceutical composition of any preceding embodiment wherein thecrosslinked amine polymer has a chloride binding capacity of at least 3mmol/g in an aqueous simulated small intestine organic and inorganicbuffer (“SOB”) containing 50 mM 2-(N-morpholino)ethanesulfonic acid(MES), 50 mM sodium acetate, 36 mM sodium chloride, 7 mM sodiumphosphate, 1.5 mM sodium citrate, 30 mM oleic acid and 5 mM sodiumtaurocholate, buffered to pH 6.2 and at 37° C.

Embodiment 58

The pharmaceutical composition of any preceding embodiment wherein thecrosslinked amine polymer has a chloride binding capacity of at least 4mmol/g in an aqueous simulated small intestine organic and inorganicbuffer (“SOB”) containing 50 mM 2-(N-morpholino)ethanesulfonic acid(MES), 50 mM sodium acetate, 36 mM sodium chloride, 7 mM sodiumphosphate, 1.5 mM sodium citrate, 30 mM oleic acid and 5 mM sodiumtaurocholate, buffered to pH 6.2 and at 37° C.

Embodiment 59

The pharmaceutical composition of any preceding embodiment wherein thecrosslinked amine polymer has a chloride binding capacity of at least 5mmol/g in an aqueous simulated small intestine organic and inorganicbuffer (“SOB”) containing 50 mM 2-(N-morpholino)ethanesulfonic acid(MES), 50 mM sodium acetate, 36 mM sodium chloride, 7 mM sodiumphosphate, 1.5 mM sodium citrate, 30 mM oleic acid and 5 mM sodiumtaurocholate, buffered to pH 6.2 and at 37° C. .

Embodiment 60

The pharmaceutical composition of any preceding embodiment wherein thepercentage of quaternized amines is less than 40%.

Embodiment 61

The pharmaceutical composition of any preceding embodiment wherein thepercentage of quaternized amines is less than 30%.

Embodiment 62

The pharmaceutical composition of any preceding embodiment wherein thepercentage of quaternized amines is less than 20%.

Embodiment 63

The pharmaceutical composition of any preceding embodiment wherein thepercentage of quaternized amines is less than 10%.

Embodiment 64

The pharmaceutical composition of any preceding embodiment wherein thepercentage of quaternized amines is less than 5%.

Embodiment 65

The pharmaceutical composition of any preceding embodiment wherein thecrosslinked amine polymer is a gel or a bead having a mean particle sizeof 40 to 180 micrometers.

Embodiment 66

The pharmaceutical composition of any preceding embodiment wherein thecrosslinked amine polymer is a gel or a bead having a mean particle sizeof 60 to 160 micrometers.

Embodiment 67

The pharmaceutical composition of any preceding embodiment wherein thecrosslinked amine polymer is a gel or a bead having a mean particle sizeof 80 to 140 micrometers.

Embodiment 68

The pharmaceutical composition of any one of embodiments 65-67 whereinless than about 0.5 volume percent of the particles have a diameter ofless than about 10 micrometers.

Embodiment 69

The pharmaceutical composition of any one of embodiments 65-67 whereinless than about 5 volume percent of the particles have a diameter ofless than about 20 micrometers.

Embodiment 70

The pharmaceutical composition of any one of embodiments 65-67 whereinless than about 0.5 volume percent of the particles have a diameter ofless than about 20 micrometers.

Embodiment 71

The pharmaceutical composition of any one of embodiments 65-67 whereinless than about 5 volume percent of the particles have a diameter ofless than about 30 micrometers.

Embodiment 72

The pharmaceutical composition of any preceding embodiment in a dosageunit form.

Embodiment 73

The pharmaceutical composition of embodiment 72 wherein the dosage unitform is a capsule, tablet or sachet dosage form.

Embodiment 74

The pharmaceutical composition of any preceding embodiment wherein thepharmaceutical composition comprises a pharmaceutically acceptablecarrier, excipient, or diluent.

Embodiment 75

A method of treating and acid/base disorder in an animal including ahuman by removing HCl through oral administration of a pharmaceuticalcomposition of any of the preceding embodiments.

Embodiment 76

The method of treatment of embodiment 75 wherein the acid/base disorderis metabolic acidosis.

Embodiment 77

The method of treatment of embodiment 75 wherein the pH is controlled ornormalized.

Embodiment 78

The method of treatment of embodiment 75 wherein the serum bicarbonateis controlled or normalized.

Embodiment 79

The method of treatment of embodiment 75 wherein less than 1 g of sodiumor potassium is administered per day.

Embodiment 80

The method of treatment of embodiment 75 wherein less than 0.5 g ofsodium or potassium is administered per day.

Embodiment 81

The method of treatment of embodiment 75 wherein less than 0.1 g ofsodium or potassium is administered per day.

Embodiment 82

The method of treatment of embodiment 75 wherein no sodium or potassiumis administered.

Embodiment 83

The method of treatment of embodiment 75 wherein the daily doseadministered is less than 20 g.

Embodiment 84

The method of treatment of embodiment 75 wherein the daily doseadministered is less than 15 g.

Embodiment 85

The method of treatment of embodiment 75 wherein the daily doseadministered is less than 10 g.

Embodiment 86

The method of treatment of embodiment 75 wherein the daily doseadministered is less than 5 g.

Embodiment 87

The method of treatment of embodiment 75 wherein the daily doseadministered is less than 4 g.

Embodiment 88

The method of treatment of embodiment 75 wherein the daily doseadministered is less than 3 g.

Embodiment 89

The method of treatment of embodiment 75 wherein the daily dose isadministered once a day.

Embodiment 90

The method of treatment of embodiment 75 wherein the daily dose isadministered twice a day.

Embodiment 91

The method of treatment of embodiment 75 wherein the daily dose isadministered three times a day.

Embodiment 92

The method of treatment of embodiment 75 wherein the metabolic acidosisis acute metabolic acidosis.

Embodiment 93

The method of treatment of embodiment 75 wherein administration ischronic.

Embodiment 94

The method of treatment of embodiment 75 wherein the daily dose resultsin a sustained serum bicarbonate increase of 21.6 mEq/L.

Embodiment 95

The method of treatment of embodiment 75 wherein the daily dose resultsin a sustained serum bicarbonate increase of ≥2 mEq/L.

Embodiment 96

The method of treatment of embodiment 75 wherein the daily dose resultsin a sustained serum bicarbonate increase of ≥3 mEq/L.

Embodiment 97

The method of treatment of embodiment 75 wherein the daily dose resultsin a sustained serum bicarbonate increase of ≥5 mEq/L.

Embodiment 98

The method of treatment of embodiment 75 wherein the daily dose resultsin a sustained serum bicarbonate increase of ≥10 mEq/L.

Embodiment 99

The method of treatment of embodiment 75 wherein a daily dose of 10 g orless per day results in an increase in serum bicarbonate of 23 mEq/L.

Embodiment 100

The method of treatment of embodiment 75 wherein a daily dose of 5 g orless per day results in an increase in serum bicarbonate of 23 mEq/L.

Embodiment 101

The method of treatment of any of embodiments 83 to 99 and the dose istitrated based on the serum bicarbonate values of the patient in need oftreatment or other indicators of acidosis.

Embodiment 102

The pharmaceutical composition of any of embodiments 1-74 wherein thecrosslinked amine polymer retains ≥1 mmol/g chloride through the GItract.

Embodiment 103

The pharmaceutical composition of any of embodiments 1-74 wherein thecrosslinked amine polymer retains ≥2 mmol/g chloride through the GItract.

Embodiment 104

The pharmaceutical composition of any of embodiments 1-74 wherein thecrosslinked amine polymer retains ≥4 mmol/g chloride through the GItract.

Embodiment 105

The pharmaceutical composition of any of embodiments 1-74 wherein thecrosslinked amine polymer retains ≥8 mmol/g chloride through the GItract.

Embodiment 106

The pharmaceutical composition of any of embodiments 1-74 wherein a doseof the pharmaceutical composition is titrated based on the serumbicarbonate values of a patient in need of treatment or other indicatorsof acidosis.

Embodiment 107

The pharmaceutical composition of any of embodiments 1-74 or the methodof embodiments 75-101 wherein an aliphatic moiety is alkyl or alkenyl.

Embodiment 108

The pharmaceutical composition of any of embodiments 1-74 or the methodof embodiments 75-101 wherein a heteroaliphatic moiety is a heteroalkylor heteroalkenyl moiety.

Having described the invention in detail, it will be apparent thatmodifications and variations are possible without departing the scope ofthe invention defined in the appended claims. Furthermore, it should beappreciated that all examples in the present disclosure are provided asnon-limiting examples.

EXAMPLES

The following non-limiting examples are provided to further illustratethe present invention. It should be appreciated by those of skill in theart that the techniques disclosed in the examples that follow representapproaches the inventors have found function well in the practice of theinvention, and thus can be considered to constitute examples of modesfor its practice. However, those of skill in the art should, in light ofthe present disclosure, appreciate that many changes can be made in thespecific embodiments that are disclosed and still obtain a like orsimilar result without departing from the spirit and scope of theinvention.

I. Preparation and Synthesis of Control Polymers

A. Free Amine Sevelamar

Renvela was obtained from commercial sources. Eighty-four sachets (i.e.201.4 gm) of Renvela (sevelamer carbonate) were poured into a 5 Lplastic beaker. Four liters of Milli-Q water were added to the beakerand the content was stirred using a magnetic stir plate and stir bar for30 minutes. The content was then transferred in to a filter frit fittedwith a P8 Whatman filter paper and excess supernatant was removed byapplying negative vacuum. The steps of adding water, stirring, filteringand removing supernatant were repeated for a total of three times. Afterthe final water wash, three liters of 1M sodium hydroxide were added tothe beaker and stirred for 30 minutes. This was followed by vacuumfiltering to remove excess sodium hydroxide. The steps of adding sodiumhydroxide, stirring and vacuum filtering were repeated for a total oftwo sodium hydroxide washes. The polymer was then washed with Milli-Qwater to remove excess sodium hydroxide. The pH of the filtrate wasmeasured using pH strips, and the polymer was washed with water untilthe pH of the filtrate was 7 or less. The wet polymer was transferredinto glass trays and frozen at −40° C. for 1 hour, and then lyophilizedfor 3-5 days to dry the polymer. The loss on drying of the polymer wasmeasured using an A&D MX-50 moisture analyzer (standard mode, ramp to130° C. and hold).

B. Bixalomer

Kiklin (Bixalomer) capsules were obtained from commercial sources andfree amine polymer was isolated directly from the capsules withoutadditional purification. Additional bixalomer reference material wasprepared following information in the Kiklin product insert(prescription information) and procedures in U.S. Pat. No. 7,459,502.The bixalomer reference material used as a comparator in severalexamples below was prepared using an epichlorohydrin (“ECH”) to1,4-Bis[bis(3-aminopropyl)amino]butane (“C4A3BTA”) molar ratio of 2.35to 1, which falls within the acceptable range of 2.4:1 to 2:1 describedin the Kiklin product insert and yielded a polymer with performanceequivalent to Kiklin as measured in the Swelling and SGF assaysdescribed above. An aqueous stock solution was made by dissolvingC4A3BTA (25.06 g), HCl (15.58 g conc. HCl), and Calimulse EM-99(branched dodecylbenzene sulfonate, 1.39 g) in water (17.99 g). A 3-neckround bottom flask with four side baffles equipped with an overheadstirrer, a Dean Stark apparatus and condenser, and a nitrogen inlet wascharged with the aqueous stock solution and toluene. The reactionmixture was stirred under inert atmosphere and heated to 80° C. ECH(17.47 g) was introduced as a 40 weight % solution in toluene which wasadded via syringe pump semi-continuously over the course of one hour.The reaction mixture was stirred for 30-45 minutes at 80° C., afterwhich the bath temperature was increased to 110° C. for a finaldehydration step. When 24 mL of water was collected, the flask wascooled to room temperature and the toluene was removed by filtration.The resultant polymer beads were purified by washing with toluene (100mL, three times), 27 wt % HCl (50 mL, three times), water (100 mL, threetimes), a solution of 10:9:1 water:methanol:NaOH (100 mL, two times),water (100 mL, five times), methanol (50 mL, three times), 20 wt % NaOH(300 mL, two times), and water until the pH of solution after washingwas 7. The beads were then dried in a lyophilizer for 48 hours. Swellingand SGF assays were used to determine the performance equivalence of thesynthesized bixalomer polymer as compared to commercial Kiklin, whichwas used “as is” from the capsule as a reference for the performance ofsynthesized polymers.

II. Chemistry Examples

The following chemistry examples are presented in five categories basedon the mechanism of polymerization used:

(a) substitution polymerization (condensation/step growth) gels

(b) substitution polymerization (condensation/step growth) beads

(c) radical polymerization (addition/chain growth) gels

(d) radical polymerization (addition/chain growth) beads

(e) post-polymerization crosslinking

In each case, a general polymerization procedure is described andspecific examples are called out with reference to tables of synthesisparameters that were varied within the general procedure. Tables of thephysicochemical performance characteristics (SGF and swelling) of theresulting polymers are also provided.

A. Substitution Polymerization of Small Molecule Amines

Under stirring, amine monomer, crosslinker, solvent, and base or acidwere added to a reaction vessel. Upon mixing, the solution was heatedand stirred. After the reaction was complete, the reaction was allowedto cool. The gel was mechanically ground to a fine powder and purifiedand dried to constant weight. Examples of amines and crosslinkers thatare suitable for the synthesis of polymers described in this exampleinclude, but are not limited to, the combinations of amines andcrosslinkers shown in Table 4. Table 5 describes key physicochemicalproperties (i.e. SGF binding and swelling ratio) of the polymer examplesshown in Table 4.

1. Specific Procedure for C2PW+DCP Gel

2-[Bis(2-aminoethyl)amino]ethanamine (“C2PW”) (1.00 g), water (1.00 g),and sodium hydroxide (1.64 g) were added to a 20 mL scintillation vialequipped with a stir bar. Under vigorous stirring, a single aliquot of1,3-Dichloropropane (“DCP”) (2.32 g) was added. Upon mixing, thesolution was heated to 80° C. and stirred vigorously for 16 hours. Thereaction was allowed to cool to 25° C. and 10 mL of water was added tothe solidified gel. The gel was mechanically ground to a fine powder.The resulting solution was centrifuged and the aqueous phase wasdecanted off. The resultant ground polymer gels were purified by washingwith methanol (100 mL, two times), water (100 mL), 1M HCl (100 mL, twotimes), water (100 mL), 1M NaOH (100 mL, three times), and finally wateruntil the pH of solution after washing was 7. This polymer is shown inTable 4 and Table 5 as polymer#37.

2. Specific Procedure for EDA3+BCPA Gel

1,2-Bis(2-aminoethylamino)ethane (“EDA3”) (0.11 g), water (0.50 g),Bis(3-chloropropyl)amine (“BCPA”) (0.50 g), and sodium hydroxide (0.19g) were added to a 20 mL scintillation vial equipped with a stir bar.Upon mixing, the solution was heated to 80° C. and stirred vigorouslyfor 16 hours. The reaction was allowed to cool to 25° C. and 10 mL ofwater was added to the solidified gel. The gel was mechanically groundto a fine powder. The resulting solution was centrifuged and the aqueousphase was decanted off. The resultant ground polymer gels were purifiedby washing with methanol (100 mL, two times), water (100 mL), 1M HCl(100 mL, two times), water (100 mL), 1M NaOH (100 mL, three times), andfinally water until the pH of the solution after washing was 7. Thispolymer is shown in Table 4 and Table 5 as polymer#54.

3. Specific Procedure for C2PW+TGA Gel

C2PW (0.50 g) and water (0.75 g) were added to a 20 mL scintillationvial equipped with a stir bar. Under vigorous stirring, a single aliquotof Tris[(2-oxiranyl)methyl]amine (“TGA”) (0.79 g) was added. Uponmixing, the solution was heated to 80° C. and stirred vigorously for 16hours. The reaction was allowed to cool to 25° C. and 10 mL of water wasadded to the solidified gel. The gel was mechanically ground to a finepowder. The resulting solution was centrifuged and the aqueous phase wasdecanted off. The resultant ground polymer gels were purified by washingwith methanol (100 mL, two times), water (100 mL), 1M HCl (100 mL, twotimes), water (100 mL), 1M NaOH (100 mL, three times), and finally wateruntil the pH of solution after washing was 7. This polymer is shown inTable 4 and Table 5 as polymer#71.

TABLE 4 Synthesis of substitution polymerization (condensation/stepgrowth) gels Polymer Amine Crosslinker Solvent 37% NaOH # AmineCrosslinker Solvent (g) (g) (g) HCl (g) (g) 1 PDA1 ECH Water 0.27 0.500.50 0.00 0.00 2 PDA1 ECH Water 0.23 0.50 0.50 0.00 0.00 3 PDA1 ECHWater 0.20 0.50 0.50 0.00 0.00 4 PDA1 ECH Water 0.18 0.50 0.50 0.00 0.005 PDA1 ECH Water 0.16 0.50 0.50 0.00 0.00 6 C4A3BTA ECH Water 0.50 0.340.60 0.12 0.00 7 C4A3BTA ECH Water 0.50 0.48 0.60 0.12 0.00 8 C4A3BTAECH Water 0.50 0.63 0.60 0.12 0.00 9 C4A3BTA ECH Water 0.50 0.77 0.600.12 0.00 10 C4A3BTA ECH Water 0.50 0.92 0.60 0.12 0.00 11 C4A3BTA ECHWater 0.50 1.07 0.60 0.12 0.00 12 C4A3BTA DCP Water 0.50 0.41 0.72 0.000.29 13 C4A3BTA DCP Water 0.50 0.50 0.72 0.00 0.35 14 C4A3BTA DCP Water0.50 0.59 0.72 0.00 0.42 15 C4A3BTA DCP Water 0.50 0.68 0.72 0.00 0.4816 C4A3BTA DCP Water 0.50 0.77 0.72 0.00 0.54 17 C4A3BTA DCP Water 0.500.95 0.72 0.00 0.67 18 C4A3BTA DCP Water 0.50 1.12 0.72 0.00 0.80 19C4A3BTA DCP Water 0.50 1.30 0.72 0.00 0.92 20 PDA1 DCP Water 0.29 0.500.50 0.00 0.35 21 PDA1 DCP Water 0.16 0.50 0.52 0.00 0.35 22 PDA1 DCPWater 0.11 0.50 0.46 0.00 0.35 23 PDA1 DCP Water 0.08 0.50 0.44 0.000.35 24 PDA1 DCP Water 0.07 0.50 0.42 0.00 0.35 25 PDA1 DCP Water 0.060.50 0.41 0.00 0.35 26 EDA1 DCP Water 0.50 1.41 0.72 0.00 1.00 27 EDA1DCP Water 0.50 1.65 0.72 0.00 1.17 28 EDA1 DCP Water 0.50 1.88 0.72 0.001.33 29 EDA2 DCP Water 0.50 0.82 0.72 0.00 0.58 30 EDA2 DCP Water 0.500.96 0.72 0.00 0.68 31 EDA2 DCP Water 0.50 1.10 0.72 0.00 0.78 32 EDA3DCP Water 1.00 1.55 1.00 0.00 1.09 33 EDA3 DCP Water 1.00 1.93 1.00 0.001.37 34 EDA3 DCP Water 1.00 2.32 1.00 0.00 1.64 35 EDA3 DCP Water 1.002.70 1.00 0.00 1.91 36 C2PW DCP Water 1.00 1.93 1.00 0.00 1.37 37 C2PWDCP Water 1.00 2.32 1.00 0.00 1.64 38 C2PW DCP Water 1.00 2.70 1.00 0.001.91 39 C2PW DCP Water 1.00 3.09 1.00 0.00 2.19 40 C2PW DCP Water 1.003.48 1.00 0.00 2.46 41 C2PW DCP Water 1.00 3.86 1.00 0.00 2.74 42C4A3BTA BCPA Water 0.26 0.50 0.50 0.00 0.19 43 C4A3BTA BCPA Water 0.150.50 0.50 0.00 0.19 44 C4A3BTA BCPA Water 0.11 0.50 0.50 0.00 0.19 45C4A3BTA BCPA Water 0.09 0.50 0.50 0.00 0.19 46 PDA1 BCPA Water/MeOH 0.060.50 0.23/0.03 0.00 0.19 47 PDA1 BCPA Water/MeOH 0.05 0.50 0.22/0.020.00 0.19 48 PDA1 BCPA Water/MeOH 0.04 0.50 0.21/0.02 0.00 0.19 49 C2PWBCPA Water 0.09 0.50 0.50 0.00 0.19 50 C2PW BCPA Water 0.06 0.50 0.500.00 0.19 51 C2PW BCPA Water 0.04 0.50 0.50 0.00 0.19 52 C2PW BCPA Water0.04 0.50 0.50 0.00 0.19 53 EDA3 BCPA Water 0.17 0.50 0.50 0.00 0.19 54EDA3 BCPA Water 0.11 0.50 0.50 0.00 0.19 55 EDA3 BCPA Water 0.08 0.500.50 0.00 0.19 56 EDA3 BCPA Water 0.07 0.50 0.50 0.00 0.19 57 C4A3BTABCPA Water 0.11 0.75 0.75 0.00 0.29 58 C4A3BTA BCPA Water 0.10 0.75 0.750.00 0.29 59 C4A3BTA BCPA Water 0.09 0.75 0.75 0.00 0.29 60 EDA3 BDEWater 0.50 1.13 0.50 0.00 0.00 61 EDA3 BDE Water 0.50 1.38 0.50 0.000.00 62 EDA3 BDE Water 0.50 1.63 0.50 0.00 0.00 63 EDA3 BDE Water 0.501.88 0.50 0.00 0.00 64 C4A3BTA TGA Water 0.50 0.29 0.75 0.00 0.00 65C4A3BTA TGA Water 0.50 0.49 0.75 0.00 0.00 66 C4A3BTA TGA Water 0.500.68 0.75 0.00 0.00 67 C4A3BTA TGA Water 0.50 0.88 0.75 0.00 0.00 68PDA1 TGA Water 0.33 0.50 0.50 0.00 0.00 69 PDA1 TGA Water 0.18 0.50 0.270.00 0.00 70 PDA1 TGA Water 0.13 0.50 0.19 0.00 0.00 71 C2PW TGA Water0.50 0.79 0.75 0.00 0.00 72 C2PW TGA Water 0.50 1.11 0.75 0.00 0.00 73C2PW TGA Water 0.50 1.42 0.75 0.00 0.00 74 EDA3 BCPA Water 0.06 0.750.75 0.00 0.29 75 EDA3 BCPA Water 0.06 0.75 0.75 0.00 0.29 76 EDA3 BCPAWater 0.05 0.75 0.75 0.00 0.29 77 C2PW BCPA Water 0.07 0.50 0.40 0.000.15 78 C3PW DCP Water 0.42 0.50 0.77 0.00 0.35 79 C3PW DCP Water 0.330.50 0.69 0.00 0.35 80 C3PW DCP Water 0.28 0.50 0.63 0.00 0.35 81 C3PWDCP Water 0.24 0.50 0.59 0.00 0.35 82 C2PW DC2OH DMF 1.00 1.32 3.00 0.000.00 83 C2PW DC2OH DMF 1.00 2.21 3.00 0.00 0.00 84 C2PW DC2OH DMF 1.002.64 3.00 0.00 0.00 85 C2PW DC2OH DMF 1.00 3.09 3.00 0.00 0.00 86 C2PWECH Water 1.00 1.58 1.50 0.00 0.00 87 C2PW ECH Water 1.00 1.90 1.50 0.000.00 88 C2PW ECH Water 1.00 2.21 1.50 0.00 0.00 89 C2A3BTA ECH Water0.50 0.51 0.21 0.39 0.00 90 C2A3BTA ECH Water 0.50 0.66 0.21 0.39 0.0091 C2A3BTA ECH Water 0.50 0.82 0.21 0.39 0.00 92 C2A3G2 ECH Water 0.500.41 1.43 0.08 0.00 93 C2A3G2 ECH Water 0.50 0.55 1.43 0.08 0.00 94C2A3G2 ECH Water 0.50 0.69 1.43 0.08 0.00

TABLE 5 Properties of substitution polymerization (condensation/stepgrowth) gels Theoretical Polymer Weight % Capacity SGF Cl # AmineCrosslinker Crosslinker MW/N (mmol/g) (mmol/g) Swelling 1 PDA1 ECH 54.7%79.6 12.6 12.4 1.8 2 PDA1 ECH 58.5% 86.9 11.5 11.0 1.4 3 PDA1 ECH 61.7%94.1 10.6 10.0 1.6 4 PDA1 ECH 64.4% 101.4 9.9 9.8 1.4 5 PDA1 ECH 66.8%108.7 9.2 9.3 1.8 6 C4A3BTA ECH 29.7% 74.9 13.3 13.4 1.9 7 C4A3BTA ECH37.8% 84.6 11.8 11.8 1.4 8 C4A3BTA ECH 44.1% 94.3 10.6 10.7 1.5 9C4A3BTA ECH 49.3% 104.0 9.6 10.0 1.3 10 C4A3BTA ECH 53.7% 113.7 8.8 9.21.6 11 C4A3BTA ECH 57.3% 123.3 8.1 8.8 1.9 12 C4A3BTA DCP 23.4% 68.814.5 14.7 1.7 13 C4A3BTA DCP 27.2% 72.3 13.8 14.5 1.4 14 C4A3BTA DCP30.5% 75.8 13.2 13.5 1.7 15 C4A3BTA DCP 33.6% 79.3 12.6 12.8 1.6 16C4A3BTA DCP 36.4% 82.8 12.1 11.9 1.8 17 C4A3BTA DCP 41.4% 89.8 11.1 10.61.2 18 C4A3BTA DCP 45.6% 96.9 10.3 10.9 1.8 19 C4A3BTA DCP 49.3% 103.99.6 9.0 1.6 20 PDA1 DCP 50.5% 72.9 13.7 12.9 4.1 21 PDA1 DCP 53.9% 78.112.8 13.0 1.8 22 PDA1 DCP 63.6% 99.2 10.1 11.4 1.4 23 PDA1 DCP 70.0%120.2 8.3 9.6 1.6 24 PDA1 DCP 74.5% 141.3 7.1 9.2 2.4 25 PDA1 DCP 77.8%162.3 6.2 8.3 2.9 26 EDA1 DCP 51.2% 61.6 16.2 12.1 3.4 27 EDA1 DCP 55.1%66.9 15.0 13.0 2.5 28 EDA1 DCP 58.3% 72.1 13.9 10.7 2.5 29 EDA2 DCP41.6% 58.9 17.0 13.7 2.8 30 EDA2 DCP 47.9% 66.0 15.2 11.8 2.5 31 EDA2DCP 52.9% 73.0 13.7 10.9 2.3 32 EDA3 DCP 36.5% 57.6 17.4 11.8 2.1 33EDA3 DCP 41.8% 62.9 15.9 11.5 2.9 34 EDA3 DCP 46.3% 68.1 14.7 10.6 2.535 EDA3 DCP 50.2% 73.4 13.6 10.0 2.5 36 C2PW DCP 41.8% 62.9 15.9 13.22.2 37 C2PW DCP 46.3% 68.1 14.7 12.1 2.4 38 C2PW DCP 50.2% 73.4 13.611.1 2.0 39 C2PW DCP 53.5% 78.6 12.7 10.1 1.6 40 C2PW DCP 56.4% 83.911.9 9.4 1.6 41 C2PW DCP 59.0% 89.2 11.2 8.8 2.1 42 C4A3BTA BCPA 48.5%68.2 14.7 15.2 3.4 43 C4A3BTA BCPA 61.1% 73.8 13.5 13.5 2.3 44 C4A3BTABCPA 68.7% 77.7 12.9 12.9 2.0 45 C4A3BTA BCPA 73.9% 80.6 12.4 11.6 1.846 PDA1 BCPA 80.5% 73.9 13.5 13.8 2.6 47 PDA1 BCPA 84.6% 78.1 12.8 12.92.4 48 PDA1 BCPA 87.3% 81.1 12.3 12.1 1.8 49 C2PW BCPA 73.1% 67.9 14.712.7 2.0 50 C2PW BCPA 80.3% 74.1 13.5 12.2 1.5 51 C2PW BCPA 84.4% 78.312.8 11.4 1.3 52 C2PW BCPA 87.2% 81.3 12.3 10.9 1.3 53 EDA3 BCPA 67.0%63.4 15.8 10.0 3.3 54 EDA3 BCPA 75.3% 69.7 14.3 10.3 2.9 55 EDA3 BCPA80.3% 74.1 13.5 12.2 3.3 56 EDA3 BCPA 83.6% 77.4 12.9 10.6 2.9 57C4A3BTA BCPA 76.7% 82.3 12.2 11.8 1.8 58 C4A3BTA BCPA 79.0% 83.7 12.012.0 1.4 59 C4A3BTA BCPA 80.9% 84.9 11.8 10.9 1.5 60 EDA3 BDE 57.0% 85.011.8 6.2 1.5 61 EDA3 BDE 61.8% 95.7 10.4 5.4 1.9 62 EDA3 BDE 65.7% 106.59.4 5.1 1.9 63 EDA3 BDE 68.8% 117.27 8.53 4.3 1.6 64 C4A3BTA TGA 37.0%71.60 13.97 12.4 3.1 65 C4A3BTA TGA 49.3% 81.39 12.29 11.3 2.0 66C4A3BTA TGA 57.7% 89.74 11.14 9.6 1.7 67 C4A3BTA TGA 63.7% 96.85 10.339.2 1.5 68 PDA1 TGA 60.7% 70.47 14.19 11.7 4.7 69 PDA1 TGA 73.9% 88.9811.24 9.4 1.4 70 PDA1 TGA 80.4% 102.35 9.77 8.3 1.2 71 C2PW TGA 61.3%71.95 13.90 10.0 1.7 72 C2PW TGA 68.9% 81.80 12.22 8.6 1.4 73 C2PW TGA74.0% 90.08 11.10 7.6 1.3 74 EDA3 BCPA 85.2% 79.14 12.64 10.3 1.6 75EDA3 BCPA 86.6% 80.63 12.40 9.9 1.9 76 EDA3 BCPA 87.7% 81.90 12.21 9.31.6 77 C2PW BCPA 77.2% 71.35 14.02 11.5 2.2 78 C3PW DCP 30.9% 68.1014.70 16.0 2.2 79 C3PW DCP 35.8% 73.40 13.60 15.3 1.9 80 C3PW DCP 40.1%78.60 12.70 14.8 1.9 81 C3PW DCP 43.9% 83.90 11.90 14.3 2.0 82 C2PWDC2OH 37.3% 58.34 17.14 11.5 4.2 83 C2PW DC2OH 49.8% 72.86 13.73 10.13.4 84 C2PW DC2OH 54.4% 80.12 12.48 9.4 3.1 85 C2PW DC2OH 58.2% 87.3811.44 9.1 3.6 86 C2PW ECH 49.8% 72.86 13.73 9.1 1.7 87 C2PW ECH 54.4%80.12 12.48 8.5 1.6 88 C2PW ECH 58.2% 87.38 11.44 7.8 1.8 89 C2A3BTA ECH40.0% 79.9 12.5 11.4 1.9 90 C2A3BTA ECH 46.4% 89.6 11.2 10.9 1.8 91C2A3BTA ECH 51.7% 99.3 10.1 10.0 1.8 92 C2A3G2 ECH 33.8% 73.9 13.5 10.42.4 93 C2A3G2 ECH 40.8% 82.6 12.1 8.1 2.0 94 C2A3G2 ECH 46.4% 91.3 11.07.3 2.3

B. General Polymerization Procedure for Beads Formed by SubstitutionPolymerization of Small Molecule Amines

An aqueous stock solution was made by dissolving amine monomer andsurfactant in water. In some instances, HCl was added to the aqueousstock solution. A reactor equipped with an overhead stirrer was chargedwith aqueous stock solution and organic solvent. Crosslinker wasintroduced in one of two methods. In the first method, crosslinker wasintroduced as part of the aqueous solution before mixing with theorganic solvent. In the second method, after beginning to heat thereactor charged with aqueous stock solution and organic solvent,crosslinker was introduced via syringe pump semi-continuously over thecourse of several hours. After the reaction was complete, the organicsolvent was removed and the beads were purified by washing the beadswith different solvents. The beads were then dried to constant weight ina lyophilizer. This procedure applies to linear and branched amines andcrosslinkers with and without an HCl binding functional group such as anamine (“active” and “passive” crosslinkers, respectively). Examples ofamines and crosslinkers that are suitable for the synthesis of polymersdescribed in this example include, but are not limited to, thecombinations of amines and crosslinkers shown in Table 6. Table 7describes key physicochemical properties (i.e. SGF binding and swellingratio) of the polymer examples shown in Table 6.

1. Specific Procedure for C4A3BTA+ECH Beads

An aqueous stock solution was made by dissolving1,4-Bis[bis(3-aminopropyl)amino]butane (“C4A3BTA”) (10.02 g), HCl (6.25g conc. HCl), and Calimulse EM-99 (branched dodecylbenzene sulfonate,0.56 g) in water (7.18 g). Round bottom flasks equipped with an overheadstirrer and condenser were charged with aqueous stock solution andtoluene. The reaction mixture was stirred under inert atmosphere andheated to 80° C. Epichlorohydrin (“ECH”) (21.37 g) was introduced as a40 weight % solution in toluene, which was added via syringe pumpsemi-continuously over the course of one hour. The reaction mixture wasstirred for 16 hours at 80° C., after which the reaction mixture wascooled to room temperature and removed from the reactor. The toluene wasremoved by decanting, and the resultant polymer beads were purified bywashing with methanol (100 mL, two times), water (100 mL), 1M HCl (100mL, two times), water (100 mL), 1M NaOH (100 mL, three times), and wateruntil the pH of solution after washing was 7. This polymer is shown inTable 6 and Table 7 as polymer number 21.

TABLE 6 Synthesis of substitution polymerization (condensation/stepgrowth) beads 37% Polymer Surf- Amine Crosslinker Solvent WaterSurfactant HCl NaOH # Amine Crosslinker Solvent actant (g) (g) (g) (g)(g) (g) (g) 1 EDA3 ECH Toluene EM-99 3.75 7.12 64.88 7.50 0.40 0.00 0.002 EDA3 ECH Toluene EM-99 3.75 8.30 64.88 7.50 0.40 0.00 0.00 3 C2PW ECHToluene EM-99 3.75 5.93 64.88 7.50 0.40 0.00 0.00 4 C2PW ECH TolueneEM-99 3.75 7.12 64.88 7.50 0.40 0.00 0.00 5 C2PW ECH Toluene EM-99 3.758.30 64.88 7.50 0.40 0.00 0.00 6 PDA1 ECH Toluene EM-99 3.00 7.49 51.906.00 0.32 0.00 0.00 7 PDA1 ECH Toluene EM-99 3.00 8.43 51.90 6.00 0.320.00 0.00 8 PDA1 ECH Toluene EM-99 3.00 9.36 51.90 6.00 0.32 0.00 0.00 9PDA1 DC2OH Toluene EM-99 3.00 10.44 74.74 18.36 0.53 0.00 6.46 10 PDA2ECH Toluene EM-99 4.00 4.23 69.20 8.00 0.43 0.00 0.00 11 PDA2 ECHToluene EM-99 4.00 7.05 69.20 8.00 0.43 0.00 0.00 12 PDA2 ECH TolueneEM-99 4.00 8.46 69.20 8.00 0.43 0.00 0.00 13 EDA1 ECH Toluene EM-99 2.006.15 52.02 6.00 0.21 0.00 0.00 14 EDA1 ECH Toluene EM-99 2.00 7.70 52.026.00 0.21 0.00 0.00 15 C4A3BTA ECH Toluene EM-99 10.03 7.32 73.38 7.420.57 6.24 0.00 16 C4A3BTA ECH Toluene EM-99 10.05 8.48 75.12 7.23 0.576.26 0.00 17 C4A3BTA ECH Toluene EM-99 10.02 9.08 86.61 7.17 0.56 6.270.00 18 C4A3BTA ECH Toluene EM-99 10.00 11.40 93.43 6.58 0.56 6.22 0.0019 C4A3BTA ECH Toluene EM-99 10.01 15.52 85.68 7.20 0.56 6.27 0.00 20C4A3BTA ECH Toluene EM-99 10.02 18.44 90.06 7.15 0.56 6.26 0.00 21C4A3BTA ECH Toluene EM-99 10.02 21.37 94.46 7.18 0.56 6.25 0.00 22C2A3BTA ECH Toluene EM-99 1.25 1.32 67.14 7.74 0.23 0.86 0.00 23 C2A3BTAECH Toluene EM-99 1.25 1.72 67.14 7.74 0.23 0.86 0.00 24 C2A3BTA ECHToluene EM-99 1.25 1.93 67.14 7.74 0.23 0.86 0.00 25 C2A3BTA ECH TolueneEM-99 1.25 2.13 67.14 7.74 0.23 0.86 0.00 26 C2A3BTA ECH Toluene EM-991.25 2.53 67.14 7.74 0.23 0.86 0.00 27 C2A3BTA ECH Toluene EM-99 1.252.93 67.14 7.74 0.23 0.86 0.00

TABLE 7 Properties of substitution polymerization (condensation/stepgrowth) beads Theoretical Polymer Weight % Capacity SGF Cl # ElementAmine Crosslinker MW/N Crosslinker (mmol/g) (mmol/g) Swelling 1 A4 EDA3ECH 54.4% 80.1 12.5 8.4 3.4 2 A5 EDA3 ECH 58.2% 87.4 11.4 7.9 2.9 3 A3C2PW ECH 49.8% 72.9 13.7 11.0 2.3 4 A4 C2PW ECH 54.4% 80.1 12.5 9.8 1.85 A5 C2PW ECH 58.2% 87.4 11.4 8.1 2.0 6 A4 PDA1 ECH 61.7% 94.1 10.6 10.91.6 7 A5 PDA1 ECH 64.4% 101.4 9.9 10.2 1.5 8 A6 PDA1 ECH 66.8% 108.7 9.29.9 1.4 9 A2 PDA1 DC2OH 61.7% 94.1 10.6 8.7 3.5 10 A1 PDA2 ECH 39.9%72.8 13.7 11.9 3.2 11 A3 PDA2 ECH 52.5% 92.1 10.9 10.9 2.7 12 A4 PDA2ECH 57.0% 101.8 9.8 10.1 2.9 13 A3 EDA1 ECH 65.9% 88.1 11.3 10.1 3.5 14A4 EDA1 ECH 70.7% 102.7 9.7 9.0 2.0 15 A1 C4A3BTA ECH 31.5% 76.9 13.012.6 2.0 16 A1 C4A3BTA ECH 34.8% 80.7 12.4 13.4 1.9 17 A1 C4A3BTA ECH36.3% 82.7 12.1 11.7 1.6 18 A1 C4A3BTA ECH 41.8% 90.4 11.1 12.2 1.9 19A1 C4A3BTA ECH 49.3% 104.0 9.6 11.0 0.9 20 A1 C4A3BTA ECH 53.7% 113.78.8 8.9 1.1 21 A1 C4A3BTA ECH 57.3% 123.3 8.1 8.2 1.2 22 A3 C2A3BTA ECH40.0% 79.9 12.5 12.8 3.5 23 A4 C2A3BTA ECH 46.4% 89.6 11.2 12.4 2.9 24A1 C2A3BTA ECH 49.2% 94.5 10.6 12.3 3.7 25 A2 C2A3BTA ECH 51.7% 99.310.1 11.5 3.1 26 A3 C2A3BTA ECH 56.0% 109.0 9.2 11.4 1.8 27 A4 C2A3BTAECH 59.5% 118.7 8.4 10.6 1.8

C. General Polymerization Procedure for Gels Formed by RadicalPolymerization (Addition/Chain Growth)

An aqueous solution of monoallylamine hydrochloride, multiallylaminecrosslinker, and a radical initiator was placed into a reaction vessel.The reaction mixture was heated, after which the vessel was cooled toroom temperature. The resulting polymer gel was swollen in water andground to a fine powder. The resultant gel was purified by washing andthen dried to a constant weight. Examples of amines that are suitablefor the synthesis of polymers described in this example include, but arenot limited to, the amines shown in Table 8. Table 9 describes keyphysicochemical properties (i.e. SGF binding and swelling ratio) of thepolymer examples shown in Table 8.

1. Specific Procedure for AAH+TAA Gel

A round bottom flask in a parallel reactor equipped with a magnetic stirbar and nitrogen inlet was charged with water (2.14 g), allylaminehydrochloride (1-(Allylamino)-2-aminoethane, “AAH”) (0.55 g),triallylamine (“TAA”) (0.71 g), concentrated HCl (0.15 g), and V-50(2,2′-Azobis(2-methylpropionamidine)dihydrochloride) (0.068 g). Thereaction mixture was sparged with nitrogen for 15 minutes and heated to80° C. under inert atmosphere. After 16 hours, the vessel was cooled toroom temperature and removed from the reactor. The polymer gel wasswollen in water and mechanically ground. The resultant fine powder waspurified by washing with methanol (100 mL, two times), water (100 mL),1M HCl (100 mL, two times), water (100 mL), 1M NaOH (100 mL, threetimes), and water until the pH of solution after washing was 7. The gelwas dried in a lyophilizer for 48 h. This polymer is shown in Table 8and Table 9 as polymer number 10.

2. Specific Procedure for AAH+DAEDA1 Gel

A round bottom flask in a parallel reactor equipped with a magnetic stirbar and nitrogen inlet was charged with water (2.53 g), allylaminehydrochloride (1-(Allylamino)-2-aminoethane, “AAH”) (0.54 g),1,2-Bis(allylamino)ethane (“DAEDA1”) (0.86 g), and V-50(2,2′-Azobis(2-methylpropionamidine)dihydrochloride) (0.067 g). Thereaction mixture was sparged with nitrogen for 15 minutes and thenheated to 80° C. under inert atmosphere. After 16 hours, the vessel wascooled to room temperature and removed from the reactor. The polymer gelwas swollen in water and mechanically ground. The resultant fine powderwas purified by washing with methanol (100 mL, two times), water (100mL), 1M HCl (100 mL, two times), water (100 mL), 1M NaOH (100 mL, threetimes), and water until the pH of solution after washing was 7. The gelwas dried in a lyophilizer for 48 hours. This polymer is shown in Table8 and Table 9 as polymer number 2.

TABLE 8 Synthesis of radical polymerization (addition/chain growth) gels37% Polymer Amine Crosslinker Water V-50 HCl # Amine Crosslinker (g) (g)(g) (g) (g) 1 AAH DAEDA1 0.66 0.74 2.53 0.071 0.00 2 AAH DAEDA1 0.540.86 2.53 0.067 0.00 3 AAH DAPDA 0.57 0.69 2.28 0.062 0.00 4 AAH DAPDA0.46 0.80 2.28 0.057 0.00 5 AAH DAPDA 0.37 0.89 2.29 0.053 0.00 6 AAHDAPDA 0.32 0.94 2.29 0.051 0.00 7 AAH DAPDA 0.19 1.07 2.29 0.046 0.00 8AAH TAA 0.78 0.48 2.17 0.076 0.10 9 AAH TAA 0.66 0.61 2.15 0.072 0.13 10AAH TAA 0.55 0.71 2.14 0.068 0.15 V-50 =2,2′-Azobis(2-methylpropionamidine)dihydrochloride

TABLE 9 Properties of radical polymerization (addition/chain growth)gels Theoretical Weight % Capacity SGF Cl Polymer # Amine CrosslinkerCrosslinker MW/N (mmol/g) (mmol/g) Swelling 1 AAH TAA 44.5% 61.7 16.210.6 3.6 2 AAH DAEDA1 63.1% 64.6 15.5 15.5 3.2 3 AAH DAPDA 57.1% 67.014.9 14.6 2.7 4 AAH DAPDA 65.3% 68.7 14.6 14.2 4.0 5 AAH DAPDA 73.0%70.4 14.2 14.0 4.8 6 AAH DAPDA 76.8% 71.3 14.0 13.7 4.5 7 AAH DAPDA86.3% 73.6 13.6 13.3 4.6 8 AAH TAA 44.5% 61.7 16.2 11.3 3.4 9 AAH TAA54.2% 62.8 15.9 9.8 2.3 10 AAH TAA 62.6% 63.8 15.7 8.9 1.9

D. General Polymerization Procedure for Beads Formed by RadicalPolymerization (Addition/Chain Growth)

An aqueous stock solution was prepared by dissolving a monoallylamineand a multiallylamine crosslinker in water. A reactor equipped with astirrer was charged with aqueous stock solution and surfactant dissolvedin a hydrophobic organic suspending solvent. A solution of radicalinitiator was prepared. The two mixtures were independently sparged withnitrogen. The initiator solution was added to the reaction mixture, andsubsequently heated for up to 16 hours. A second portion of initiator beadded to the reaction mixture if necessary depending on thepolymerization kinetics. The reaction mixture can also involve adehydration step to yield a more concentrated reaction mixture andpolymerize less active monomers and crosslinkers. After cooling thevessel to room temperature, the organic phase was removed and the beadswere purified. The beads were dried. Examples of amines and crosslinkersthat are suitable for the synthesis of polymers described in thisexample include, but are not limited to, the combinations of amines andcrosslinkers shown in Table 10 part 1. These beads were then subjectedto post-polymerization crosslinking procedures as described in E, belowand in Table 10 part 2.

1. Specific Procedure for AAH+DAEDA1 Beads

An aqueous stock solution was prepared by dissolving allylaminehydrochloride (1-(Allylamino)-2-aminoethane, “AAH”) (10.94 g) and1,2-Bis(allylamino)ethane (“DAEDA1”) (6.23 g) in water (38.89 g). A3-neck round bottom flask with four side baffles equipped with anoverhead stirrer, Dean Stark apparatus and condenser, and nitrogeninlet, was charged with aqueous stock solution and surfactant (CalimulseEM-99, branched dodecylbenzene sulfonate, 3.14 g) dissolved in a 74:26chlorobenzene/heptane solution (311.11 g). In a separate vessel, asolution of V-50 (1.98 g) in water (12.75 g) was prepared. The twomixtures were independently sparged with nitrogen. Under inertatmosphere, the initiator solution was added to the reaction mixture,and subsequently heated to 67° C. for 16 hours. A second portion ofinitiator solution (14.73 g) and the reaction mixture were degassed andcombined before increasing the temperature to 115° C. for a finaldehydration step. After cooling the vessel to room temperature, theorganic phase was removed by decanting, and the beads were purified bywashing with methanol (100 mL, two times), water (100 mL), 2 M NaOH (100mL), and water (100 mL, two times). The beads were dried in alyophilizer for 48 hours. This polymer is shown in Table 10_1 and wasthe source bead for postpolymerization crosslinking that resulted inpolymers 29-31 in Table 10 Part 2.

E. General Procedure of Post-Polymerization Crosslinking of PolyamineBeads or Gels

Crosslinked polyamine beads or gels can be obtained from eithercrosslinking of linear polyamines, radical polymerization andcrosslinking or small molecule amine crosslinking via a substitutionreaction.

As a general example of polyamine bead synthesis, a stock solution oflinear polyamine hydrochloride (and optionally sodium hydroxide) andwater soluble crosslinker in water was prepared. Under inert atmosphere,a flask with an overhead stirrer was charged with each the aqueous andorganic stock solutions. After initiating stirring, the reaction washeated up to 16 hours. Optionally a dehydrating procedure/step can beadded to concentrate the reaction mixture. The hydrophobic organicsolvent was removed by decanting, and the beads were purified by washingin solvents chosen to remove impurities. The resulting polyamine beadwas deprotonated by washing with NaOH. The beads were washed with watersuch that the resulting effluent water approached neutral pH and dried.

The resulting dried polyamine bead was placed into a reactor and asolvent was added to the gel. The crosslinker was added to the resultingslurry. The mixture was heated for a required amount of time to reachcompletion. The reaction mixture was cooled and the beads were purifiedby washing and dried until no further water was removed and the weightremained constant. Examples of post-polymerization crosslinkingdescribed in this example include, but are not limited to, thecrosslinkers shown in Table 10, Part 2. Table 11 describes keyphysicochemical properties (i.e. SGF binding and swelling ratio) of thepolymer examples shown in Table 10_Part 2.

1. Post-Crosslinking of PAAH Beads with DCP

An aqueous stock solution was made by dissolving polyallylaminehydrochloride (average Mw˜15,000 (GPC vs. PEG std.)) (25 g)) and sodiumhydroxide (6.0 g) in water (75.5 g). The solution was stirred for atleast 10 minutes. A stock solution containing toluene (316 g) andsurfactant (SPAN 80 (sorbitane monooleate)) (3.2 g) was also prepared. A3-neck round bottom flask with four side baffles equipped with anoverhead stirrer, Dean Stark apparatus and condenser were charged withthe toluene solution. Dichloropropanol (1,3-Dichloro-2-propanol ,“(DC2POH”) (3.45 g) was added to the aqueous stock solution at roomtemperature and stirred for 1 minute. This solution was added to the3-neck round bottom flask set up. The reaction mixture was stirred underinert atmosphere. The reaction was heated to 50° C. for 14 hours. Afterthis time, the reaction mixture was heated to 80° C., after which thereaction mixture was heated to 115° C. for a final dehydration step.Once all the water has been removed from the reaction (75 g), thereaction was allowed to cool to room temperature. The toluene wasremoved by decanting, and the resultant polymer beads were purified bywashing with methanol (100 mL, two times), water (100 mL), 1M HCl (100mL, two times), water (100 mL), 1M NaOH (100 mL, two times), and wateruntil the pH of solution after washing was 7. The beads were dried in alyophilizer for 48 hours.

0.40 g of the above resulting PAAH beads were mixed with 2.8 mL ofmethanol and 1,3-Dichloropropane (“DCP”) (0.51 g) in a vial. The beadswere mixed with a spatula to obtain equally distributed wetting beforethe vial was sealed and heated to 75° C. overnight. The cooled beadswere purified by washing with methanol (45 mL, two times), water (45mL), 1M HCl (45 mL, two times), water (45 mL), 1M NaOH (45 mL, threetimes), and water until the pH of solution after washing was 7. The gelwas dried in a lyophilizer for 48 hours. This polymer is shown in Table10_Part 2 and Table 11 as polymer number 4.

1. Post-Crosslinking of PAAH Beads with DCP

An aqueous stock solution was prepared by dissolving allylaminehydrochloride (10.71 g) and 1,3-Bis(allylamino)propane (“DAPDA”) (6.50g) in water (27.88 g). A 3-neck round bottom flask with four sidebaffles equipped with an overhead stirrer, Dean Stark apparatus andcondenser, and nitrogen inlet was charged with aqueous stock solutionand surfactant (Calimulse EM-99, branched dodecylbenzene sulfonate, 3.14g) dissolved in a 74:26 chlorobenzene/heptane solution (311.11 g). In aseparate vessel, a solution of V-50 (1.94 g) in water (11.00 g) wasprepared. The two mixtures were independently sparged with nitrogen.Under inert atmosphere, the initiator solution was added to the reactionmixture, and subsequently heated to 67° C. for 16 hours. A secondportion of initiator solution (12.94 g) and the reaction mixture weredegassed and combined before increasing the temperature to 115° C. for afinal dehydration step. After cooling the vessel to room temperature,the organic phase was removed by decanting, and the beads were purifiedby washing with methanol (100 mL, two times), water (100 mL), 2 M NaOH(100 mL), and water (100 mL, two times). The beads were dried in alyophilizer for 48 hours.

1,3-Dichloropropane (“DCP”) (0.18 g) was added to a vial charged withMeOH (2.80 g) and 0.40 g of the above resulting PAAH beads. The beadswere mixed with a spatula to obtain equally distributed wetting beforethe vial was sealed and heated to 75° C. overnight. The cooled beadswere purified by washing with methanol (45 mL, two times), water (45mL), 1M HCl (45 mL, two times), water (45 mL), 1M NaOH (45 mL, twotimes), and water until the pH of solution after washing was 7. The gelwas dried in a lyophilizer for 48 hours. This polymer is shown in Table10_Part 2 and Table 11 as polymer number 10.

TABLE10 Part 1: Synthesis of radical polymerization (addition/chaingrowth) beads Source Bead Recipe Post- Crosslinked V-50 Monomer # AmineCrosslinker Solvent Surfactant Amine (g) Crosslinker 1 (g) Solvent 1 (g)Water (g) Surfactant (g) (g) 1 PAH DC2OH Toluene Span80 25.00 3.45315.96 75.43 3.19 0.00 2 PAH DC2OH Toluene Span80 25.00 3.45 315.9675.43 3.19 0.00 3 PAH DC2OH Toluene Span80 25.00 3.45 315.96 75.43 3.190.00 4 PAH DC2OH Toluene Span80 25.00 3.45 315.96 75.43 3.19 0.00 5 PAHBCPA 3:1 PhCl:Heptane Span80 2.64 1.16 70.00 10.00 0.71 0.00 6 AAH DAPDA3:1 PhCl:Heptane EM-99 10.71 6.50 311.11 38.89 3.14 1.94 7 AAH DAPDA 3:1PhCl:Heptane EM-99 10.71 6.50 311.11 38.89 3.14 1.94 8 AAH DAPDA 3:1PhCl:Heptane EM-99 10.71 6.50 311.11 38.89 3.14 1.94 9 AAH DAPDA 3:1PhCl:Heptane EM-99 10.71 6.50 311.11 38.89 3.14 1.94 10 AAH DAPDA 3:1PhCl:Heptane EM-99 10.71 6.50 311.11 38.89 3.14 1.94 11 AAH DAPDA 3:1PhCl:Heptane EM-99 10.71 6.50 311.11 38.89 3.14 1.94 12 AAH DAPDA 3:1PhCl:Heptane EM-99 10.71 6.50 311.11 38.89 3.14 1.94 13 AAH DAPDA 3:1PhCl:Heptane EM-99 12.30 9.95 300.00 50.00 3.03 2.38 14 AAH DAPDA 3:1PhCl:Heptane EM-99 12.30 9.95 300.00 50.00 3.03 2.38 15 AAH DAPDA 3:1PhCl:Heptane EM-99 12.30 9.95 300.00 50.00 3.03 2.38 16 AAH DAPDA 3:1PhCl:Heptane EM-99 12.30 9.95 300.00 50.00 3.03 2.38 17 AAH DAPDA 3:1PhCl:Heptane EM-99 12.30 9.95 300.00 50.00 3.03 2.38 18 AAH DAPDA 3:1PhCl:Heptane EM-99 12.30 9.95 300.00 50.00 3.03 2.38 19 AAH DAPDA 3:1PhCl:Heptane EM-99 12.30 9.95 300.00 50.00 3.03 2.38 20 AAH DAPDA 3:1PhCl:Heptane EM-99 12.30 9.95 300.00 50.00 3.03 2.38 21 AAH DAPDA 3:1PhCl:Heptane EM-99 10.96 11.40 300.00 50.00 3.03 2.27 22 AAH DAPDA 3:1PhCl:Heptane EM-99 10.96 11.40 300.00 50.00 3.03 2.27 23 AAH DAPDA 3:1PhCl:Heptane EM-99 10.96 11.40 300.00 50.00 3.03 2.27 24 AAH DAPDA 3:1PhCl:Heptane EM-99 10.96 11.40 300.00 50.00 3.03 2.27 25 AAH DAPDA 3:1PhCl:Heptane EM-99 10.96 11.40 300.00 50.00 3.03 2.27 26 AAH DAPDA 3:1PhCl:Heptane EM-99 10.96 11.40 300.00 50.00 3.03 2.27 27 AAH DAPDA 3:1PhCl:Heptane EM-99 10.96 11.40 300.00 50.00 3.03 2.27 28 Sevelamer, freeamine form, excipient removed 29 AAH DAEDA1 3:1 PhCl:Heptane EM-99 10.946.23 311.11 38.89 3.14 1.98 30 AAH DAEDA1 3:1 PhCl:Heptane EM-99 10.946.23 311.11 38.89 3.14 1.98 31 AAH DAEDA1 3:1 PhCl:Heptane EM-99 10.946.23 311.11 38.89 3.14 1.98 32 C2PW ECH Toluene EM-99 3.75 3.56 64.887.50 0.40 0.00 33 C2PW ECH Toluene EM-99 3.75 4.75 64.88 7.50 0.40 0.0034 C2PW ECH Toluene EM-99 3.75 4.75 64.88 7.50 0.40 0.00 35 C2PW ECHToluene EM-99 3.75 4.75 64.88 7.50 0.40 0.00 36 C2PW ECH Toluene EM-993.75 4.75 64.88 7.50 0.40 0.00 37 C2PW ECH Toluene EM-99 3.75 5.93 64.887.50 0.40 0.00 38 C2PW ECH Toluene EM-99 3.75 5.93 64.88 7.50 0.40 0.0039 C2PW ECH Toluene EM-99 3.75 7.12 64.88 7.50 0.40 0.00 40 C2PW ECHToluene EM-99 3.75 7.12 64.88 7.50 0.40 0.00 41 C2PW ECH Toluene EM-998.33 7.91 72.08 16.67 0.30 0.00 42 PDA1 ECH Toluene EM-99 3.00 4.6851.90 6.00 0.32 0.00 43 PDA1 ECH Toluene EM-99 3.00 4.68 51.90 6.00 0.320.00 44 PDA1 ECH Toluene EM-99 3.00 5.62 51.90 6.00 0.32 0.00 45 PDA1ECH Toluene EM-99 3.00 5.62 51.90 6.00 0.32 0.00 46 PDA1 ECH TolueneEM-99 3.00 6.55 51.90 6.00 0.32 0.00 47 PDA1 ECH Toluene EM-99 3.00 6.5551.90 6.00 0.32 0.00 48 PDA1 ECH Toluene EM-99 3.00 7.49 51.90 6.00 0.320.00 49 PDA1 ECH Toluene EM-99 3.00 7.49 51.90 6.00 0.32 0.00 V-50:2,2′-Azobis(2-methylpropionamidine)dihydrochloride

TABLE 10_Part 2 Synthesis of radical polymerization (addition/chaingrowth) beads (Contd.) Post- Secondary Crosslinking Recipe CrosslinkedBead Crosslinker Solvent Monomer # Crosslinker Solvent (g) (g) (g) 1 DCPMeOH 0.40 0.01 2.80 2 DCP MeOH 0.40 0.18 2.80 3 DCP MeOH 0.40 0.34 2.804 DCP MeOH 0.40 0.51 2.80 5 DCP H2O 0.40 0.46 0.40 6 DCP H2O 0.40 0.012.80 7 DCP H2O 0.40 0.18 2.80 8 DCP H2O 0.40 0.34 2.80 9 DCP H2O 0.400.51 2.80 10 DCP MeOH 0.40 0.18 2.80 11 DCP MeOH 0.40 0.34 2.80 12 DCPMeOH 0.40 0.51 2.80 13 DCP H2O 0.40 0.47 0.40 14 DCP H2O 0.40 0.47 0.8015 DCP H2O 0.40 0.47 1.20 16 DCP H2O 0.40 0.47 1.60 17 DCP MeOH 0.400.16 2.80 18 DCP MeOH 0.40 0.32 2.80 19 DCP MeOH 0.40 0.47 2.80 20 DCPDMF 0.40 0.47 1.20 21 DCP H2O 0.40 0.46 0.10 22 DCP H2O 0.40 0.46 0.2023 DCP H2O 0.40 0.46 0.30 24 DCP H2O 0.40 0.46 0.40 25 DCP H2O 0.40 0.460.50 26 DCP H2O 0.40 0.46 0.60 27 DCP 50% NaOH 0.80 0.46 0.40 28 DCP 50%NaOH 0.80 0.51 0.40 29 DCP H2O 0.40 0.50 0.20 30 DCP H2O 0.40 0.50 0.4031 DCP H2O 0.40 0.50 0.60 32 DCP H2O 0.40 1.17 0.40 33 DCP H2O 0.40 0.340.40 34 DCP H2O 0.40 0.68 0.40 35 DCP H2O 0.40 0.34 0.20 36 DCP H2O 0.400.68 0.20 37 DCP H2O 0.40 0.31 0.40 38 DCP H2O 0.40 0.62 0.40 39 DCP H2O0.40 0.28 0.40 40 DCP H2O 0.40 0.57 0.40 41 DCP Neat 0.90 4.38 0.00 42DCP H2O 0.40 0.47 0.40 43 DCP H2O 0.40 0.78 0.40 44 DCP H2O 0.40 0.280.40 45 DCP H2O 0.30 0.42 0.30 46 DCP H2O 0.40 0.13 0.40 47 DCP H2O 0.400.39 0.40 48 DCP H2O 0.40 0.24 0.40 49 DCP H2O 0.40 0.48 0.40

TABLE 11 Properties of radical polymerization (addition/chain growth)beads Post- Total Theoretical SGF Crosslinked Weight % MW/ Capacity (Cl)Swell- Polymer # Crosslinker N (mmol/g) (mmol/g) ing 1 14.9% 67.1 14.912.2 2.2 2 23.1% 74.3 13.5 11.7 2.0 3 33.3% 85.6 11.7 11.1 1.7 4 40.9%96.6 10.4 10.8 1.9 5 45.9% 88.0 11.4 15.7 2.7 6 51.0% 83.2 12.0 11.3 1.47 51.0% 83.2 12.0 14.7 2.2 8 51.0% 83.2 12.0 14.7 3.1 9 51.0% 83.2 12.014.5 3.5 10 42.5% 70.9 14.1 13.7 3.2 11 48.4% 79.0 12.7 13.0 3.2 1251.0% 83.2 12.0 10.8 3.2 13 54.0% 82.8 12.1 11.8 1.0 14 54.0% 82.8 12.111.8 1.5 15 54.0% 82.8 12.1 12.1 2.2 16 54.0% 82.8 12.1 11.8 3.0 1746.6% 71.3 14.0 12.6 3.1 18 51.8% 78.9 12.7 11.9 2.8 19 54.0% 82.8 12.111.8 2.8 20 54.0% 82.8 12.1 11.9 1.1 21 56.7% 82.5 12.1 11.3 0.9 2256.7% 82.5 12.1 11.9 0.8 23 56.7% 82.5 12.1 11.8 1.2 24 56.7% 82.5 12.111.3 1.1 25 56.7% 82.5 12.1 11.9 1.3 26 56.7% 82.5 12.1 11.3 1.4 2756.7% 82.5 12.1 10.6 1.6 28 36.2% 89.5 11.2 12.1 3.6 29 49.8% 81.2 12.312.3 1.9 30 49.8% 81.2 12.3 11.6 1.6 31 49.8% 81.2 12.3 11.7 1.9 3250.7% 74.1 13.5 11.0 2.0 33 48.4% 70.9 14.1 10.4 1.7 34 52.0% 76.1 13.110.4 1.6 35 48.4% 70.9 14.1 10.3 1.4 36 52.0% 76.1 13.1 10.4 1.7 3753.2% 78.1 12.8 9.9 1.9 38 56.2% 83.4 12.0 9.9 1.5 39 57.2% 85.4 11.79.2 1.5 40 59.7% 90.6 11.0 9.1 1.5 41 77.6% 163.5 6.1 11.2 1.7 42 59.1%88.1 11.3 11.8 1.5 43 63.5% 98.7 10.1 12.0 1.9 44 60.0% 90.1 11.1 11.71.4 45 64.2% 100.7 9.9 11.8 1.4 46 60.9% 92.1 10.9 11.4 1.4 47 64.9%102.7 9.7 11.3 1.2 48 65.6% 104.7 9.6 9.2 1.3 49 68.7% 115.2 8.7 10.81.2

II. Performance Examples

The following examples provide the results of evaluating selectedsynthesized polymers of the current disclosure, as well as commerciallyavailable reference polymers, in performance-evaluating screens andassays measuring chloride binding selectivity over phosphate (SIBassay), chloride binding selectivity in presence of inorganic andorganic interferents (SOB assay), total quaternary amines (QAA assay),SOB binding kinetics, and chloride retention (CRA assay). These assaysare defined above.

A. Performance Example

The following Table 12 shows examples of the relative performance ofthree selected polymers: reference bixalomer prepared as describedabove, another C4A3BTA/ECH polymer with an increased ECH mole equivalentcontent, and free amine sevelamer. The assays used to generate the datain this example are described elsewhere.

Bixalomer reference crosslinked amine polymer prepared from C4A3BTA asmonomer and ECH as crosslinker at a crosslinker molar equivalence of2.35 was shown to have a swelling ratio of 2.3 g of water/g of drypolymer and a binding capacity of 12.8 mmol/g in SGF. This polymer bound1.7 mmol/g chloride and 5.2 mmol/g phosphate in SIB and bound 0.8 mmol/gchloride, 1.4 mmol/g phosphate, 0.5 mmol/g citrate and 0.6 mmol/gtaurocholate in SOB.

By comparison, crosslinked amine polymer prepared from C4A3BTA as amonomer and ECH as a crosslinker at a crosslinker molar equivalence of5.3 was shown to have a swelling ratio of 0.9 g of water/g of drypolymer and a binding capacity of 11 mmol/g in SGF. This polymer bound1.6 mmol/g chloride and 3.2 mmol/g phosphate in SIB and bound 3 mmol/gchloride, 0.5 mmol/g phosphate, 0 mmol/g citrate and 0 mmol/gtaurocholate in SOB.

Free amine sevelamer polymer (prepared as described elsewhere) was shownto have a swelling ratio of 6.5 g of water/g of dry polymer and abinding capacity of 12.1 mmol/g in SGF. This polymer bound 1.1 mmol/gchloride and 6.1 mmol/g phosphate in SIB and bound 0.2 mmol/g chloride,0.8 mmol/g phosphate, 0.4 mmol/g citrate and 1.8 mmol/g taurocholate inSOB.

Table 13 includes example polymers of the current disclosure whoseswelling ratio is less than or equal to 2. Table 14 includes examplepolymers of the current disclosure whose swelling ratio is greater than2, but less than or equal to 5.

TABLE 12 Comparative Performance of Selected Polymers SGF Cl SIB PO4 SOBXlinker Swelling BC SIB Cl BC BC SOB Cl SOB PO4 Citrate SOB TC MonomerCrosslinker Mol. Eq. (g/g) (mmol/g) (mmol/g) (mmol/g) (mmol/g) (mmol/g)(mmol/g) (mmol/g) C4A3BTA ECH 2.35 2.3 12.8 1.7 5.2 0.8 1.4 0.5 0.6C4A3BTA ECH 5.3 0.9 11.0 1.6 3.2 3.0 0.5 0.0 0.0 Sevelamer free amineform - 6.5 12.1 1.1 6.1 0.2 0.8 0.4 1.8 excipient removed

TABLE 13 Example polymers of the current disclosure whose swelling ratiois less than or equal to 2 Cross- SOB Cross- linker Swell- SIB Cl SIBPO4 SOB Cl SOB PO4 Citrate SOB TC Monomer linker Mol. Eq. ing (mmol/g)(mmol/g) (mmol/g) (mmol/g) (mmol/g) (mmol/g) AAH TAA 0.4 1.9 2.3 4.0 0.40.4 0.3 1.4 AAH/20% DAEDA1 Bead DCP 0.7 1.6 2.5 3.2 4.4 0.1 0.0 0.1AAH/20% DAEDA1 Bead DCP 0.7 1.9 2.1 4.0 3.5 0.2 0.0 0.1 AAH/20% DAEDA1Bead DCP 0.7 1.9 2.6 3.6 4.5 0.3 0.0 0.0 AAH/20% DAPDA Bead DCP 0.7 1.42.4 4.3 3.7 0.2 0.0 0.1 AAH/25% DAPDA Bead DCP 0.7 1.0 3.1 3.5 4.1 0.20.0 0.0 AAH/25% DAPDA Bead DCP 0.7 1.1 2.2 3.8 4.3 0.1 0.0 0.0 AAH/25%DAPDA Bead DCP 0.7 1.5 2.7 4.4 3.4 0.5 0.1 0.2 AAH/30% DAPDA Bead DCP0.7 0.8 3.9 2.1 4.8 0.2 0.0 0.0 AAH/30% DAPDA Bead DCP 0.7 0.9 3.9 1.73.7 0.1 0.0 0.0 AAH/30% DAPDA Bead DCP 0.7 1.1 2.9 3.2 4.1 0.1 0.0 0.0AAH/30% DAPDA Bead DCP 0.7 1.2 3.6 2.3 4.1 0.2 0.0 0.0 AAH/30% DAPDABead DCP 0.7 1.3 2.6 3.7 3.8 0.1 0.0 0.1 AAH/30% DAPDA Bead DCP 0.7 1.42.4 4.0 3.6 0.3 0.0 0.1 AAH/30% DAPDA Bead DCP 0.7 1.6 2.3 3.0 2.7 0.40.1 0.2 C2A3BTA ECH 7.3 1.8 1.6 3.0 nm nm nm nm C2A3BTA ECH 4.3 1.8 1.52.9 nm nm nm nm C2A3BTA ECH 5.3 1.8 1.6 2.4 nm nm nm nm C2A3BTA ECH 6.31.8 1.6 3.4 nm nm nm nm C2A3BTA ECH 3.3 1.9 1.5 3.5 nm nm nm nm C2A3G2ECH 5.8 2.0 1.8 2.6 nm nm nm nm C2PW BCPA 8.0 1.3 2.2 3.2 2.2 0.3 0.00.1 C2PW BCPA 10.0 1.3 2.0 2.9 2.0 0.2 0.0 0.1 C2PW BCPA 6.0 1.5 2.2 3.62.8 0.3 0.0 0.1 C2PW BCPA 4.0 2.0 2.2 4.3 2.8 0.3 0.1 0.2 C2PW DCP 4.01.6 2.0 2.8 1.5 0.0 0.0 0.1 C2PW DCP 4.5 1.6 1.9 2.5 0.9 0.0 0.0 0.1C2PW DCP 3.5 2.0 2.1 3.4 1.7 0.2 0.0 0.1 C2PW ECH 3.0 1.6 1.5 2.6 1.60.2 0.0 0.2 C2PW ECH 2.5 1.7 1.4 3.1 1.6 0.4 0.1 0.3 C2PW ECH 3.0 1.81.6 3.4 2.1 0.2 0.0 0.4 C2PW ECH 3.5 1.8 1.7 2.1 1.4 0.1 0.0 0.2 C2PWECH 3.5 2.0 1.5 3.0 1.5 0.1 0.0 0.3 C2PW TGA 2.3 1.3 1.3 1.7 nm nm nm nmC2PW TGA 1.8 1.4 1.2 2.5 1.4 0.2 0.0 0.1 C2PW TGA 1.3 1.7 1.2 3.6 0.70.7 0.2 0.6 C2PW/ECH 1.5 eq Bead DCP 10.0 1.7 1.5 3.9 3.0 0.3 0.0 0.2C2PW/ECH 1.5 eq Bead DCP 1.5 2.0 1.5 4.2 2.1 0.4 0.1 0.4 C2PW/ECH 2 eqBead DCP 0.5 1.4 1.6 3.5 2.9 0.2 0.0 0.1 C2PW/ECH 2 eq Bead DCP 1.0 1.61.6 3.6 2.6 0.2 0.0 0.3 C2PW/ECH 2 eq Bead DCP 0.5 1.7 1.5 3.7 2.5 0.30.0 0.3 C2PW/ECH 2 eq Bead DCP 1.0 1.7 1.6 3.5 2.9 0.2 0.0 0.1 C2PW/ECH2.5 eq Bead DCP 1.0 1.5 1.6 3.1 2.7 0.2 0.0 0.2 C2PW/ECH 2.5 eq Bead DCP0.5 1.9 1.6 3.2 2.4 0.1 0.0 0.3 C2PW/ECH 3 eq Bead DCP 0.5 1.5 1.7 2.72.2 0.1 0.0 0.1 C2PW/ECH 3 eq Bead DCP 1.0 1.5 1.7 2.7 2.5 0.2 0.0 0.1C3PW DCP 2.5 1.9 1.9 5.2 3.8 0.7 0.1 0.3 C3PW DCP 3.0 1.9 2.0 4.9 3.70.4 0.1 0.2 C3PW DCP 3.5 2.0 2.1 4.4 3.4 0.3 0.0 0.2 C4A3BTA BCPA 12.01.4 2.0 3.6 3.3 0.3 0.0 0.1 C4A3BTA BCPA 13.5 1.5 1.9 3.1 2.8 0.2 0.00.1 C4A3BTA BCPA 10.5 1.8 2.0 3.5 3.3 0.3 0.0 0.1 C4A3BTA BCPA 9.0 1.8nm nm 2.8 0.3 0.0 0.4 C4A3BTA BCPA 7.0 2.0 2.1 4.3 2.9 0.5 0.1 0.4C4A3BTA DCP 5.3 1.2 2.0 3.0 1.6 0.1 0.0 0.1 C4A3BTA DCP 2.8 1.4 2.3 5.3nm nm nm nm C4A3BTA DCP 3.8 1.6 2.3 4.1 nm nm nm nm C4A3BTA DCP 7.3 1.61.5 2.7 0.6 0.1 0.0 0.3 C4A3BTA DCP 3.3 1.7 2.3 4.7 3.5 0.4 0.0 0.2C4A3BTA DCP 2.3 1.7 2.0 5.6 2.0 1.6 0.4 0.4 C4A3BTA DCP 6.3 1.8 1.9 3.41.5 0.1 0.0 0.2 C4A3BTA DCP 4.3 1.8 2.4 3.3 2.8 0.6 0.0 0.1 C4A3BTA ECH5.3 0.9 1.6 3.2 3.0 0.5 0.0 0.0 C4A3BTA ECH 6.3 1.1 1.5 3.8 1.7 0.5 0.00.0 C4A3BTA ECH 7.3 1.2 0.6 2.9 1.6 0.6 0.0 0.0 C4A3BTA ECH 5.3 1.3 1.82.7 1.8 0.1 0.0 0.1 C4A3BTA ECH 3.3 1.4 1.7 3.9 2.8 0.2 0.0 0.2 C4A3BTAECH 4.3 1.5 1.8 3.0 2.3 0.1 0.0 0.1 C4A3BTA ECH 6.3 1.6 1.9 1.9 1.4 0.00.0 0.0 C4A3BTA ECH 3.1 1.6 1.5 4.6 2.8 0.8 0.0 0.3 C4A3BTA ECH 7.3 1.91.9 1.5 1.3 0.0 0.0 0.1 C4A3BTA ECH 3.9 1.9 1.6 4.6 nm nm nm nm C4A3BTAECH 2.3 1.9 1.6 5.1 1.0 1.4 0.4 0.5 C4A3BTA ECH 2.9 1.9 1.7 4.8 2.0 1.40.2 0.4 C4A3BTA ECH 2.5 2.0 1.7 5.0 1.4 1.2 0.3 0.6 C4A3BTA TGA 3.0 1.51.5 2.5 nm nm nm nm C4A3BTA TGA 2.3 1.7 1.4 2.8 nm nm nm nm C4A3BTA TGA1.7 2.0 1.7 4.1 0.7 0.5 0.3 1.1 EDA1 ECH 2.5 2.0 1.2 2.6 nm nm nm nmEDA3 BCPA 10.5 1.6 1.6 2.5 2.3 0.4 0.1 0.1 EDA3 BCPA 8.5 1.6 1.9 2.7 2.60.3 0.0 0.1 EDA3 BCPA 9.5 1.9 1.7 2.7 2.4 0.2 0.0 0.1 EDA3 BDE 2.3 1.51.1 1.6 nm nm nm nm EDA3 BDE 3.8 1.6 0.9 0.7 nm nm nm nm EDA3 BDE 2.81.9 1.0 1.2 nm nm nm nm EDA3 BDE 3.3 1.9 1.0 1.0 nm nm nm nm PAH/10%DC2OH Bead DCP 0.5 1.7 2.1 3.9 2.8 0.1 0.0 0.1 PAH/10% DC2OH Bead DCP0.8 1.9 2.1 3.7 2.7 0.1 0.0 0.1 PAH/10% DC2OH Bead DCP 0.3 2.0 2.0 4.42.8 0.4 0.0 0.1 PDA1 BCPA 5.0 1.8 2.0 3.6 2.4 0.3 0.0 0.2 PDA1 DCP 3.01.4 1.9 3.3 2.0 0.1 0.0 0.1 PDA1 DCP 4.0 1.6 1.5 2.5 0.5 0.0 0.0 0.1PDA1 DCP 2.0 1.8 2.2 4.9 3.7 0.5 0.0 0.1 PDA1 ECH 1.8 1.4 1.2 3.2 2.10.4 0.0 0.2 PDA1 ECH 2.3 1.4 1.4 2.4 1.6 0.1 0.0 0.1 PDA1 ECH 2.5 1.42.0 3.5 2.5 0.2 0.0 0.1 PDA1 ECH 2.3 1.5 1.8 3.7 1.7 0.6 0.1 0.4 PDA1ECH 2.0 1.6 1.3 2.4 1.9 0.2 0.0 0.1 PDA1 ECH 2.0 1.6 1.8 4.1 1.1 1.1 0.30.5 PDA1 ECH 1.5 1.8 1.2 4.0 0.5 0.8 0.3 0.5 PDA1 ECH 2.5 1.8 1.4 1.81.3 0.1 0.0 0.1 PDA1 TGA 1.6 1.2 1.4 1.7 nm nm nm nm PDA1 TGA 1.1 1.41.3 2.9 1.5 0.6 0.1 0.3 PDA1/ECH 1.25 eq Bead DCP 0.8 1.5 1.6 4.0 2.60.4 0.1 0.4 PDA1/ECH 1.25 eq Bead DCP 1.3 1.9 1.8 4.2 2.5 0.5 0.1 0.4PDA1/ECH 1.5 eq Bead DCP 0.5 1.4 1.7 3.9 2.6 0.4 0.0 0.3 PDA1/ECH 1.5 eqBead DCP 1.0 1.4 1.7 3.8 2.5 0.2 0.1 0.2 PDA1/ECH 1.75 eq Bead DCP 0.81.2 1.9 3.6 2.6 0.2 0.0 0.2 PDA1/ECH 1.75 eq Bead DCP 0.3 1.4 1.8 3.72.4 0.3 0.0 0.2 PDA1/ECH 2 eq Bead DCP 1.0 1.2 1.9 5.6 1.8 0.2 0.0 0.1PDA1/ECH 2 eq Bead DCP 0.5 1.3 1.8 3.2 1.7 0.2 0.0 0.1 Cl = Chloride; P:= Phosphate; TC = Taurocholate; nm = not measured

TABLE 14 Example polymers of the current disclosure whose swelling ratiois is greater than 2, but less than or equal to 5 SOB Cross-Cross-linker Swell- SIB Cl SIB PO4 SOB Cl SOB PO4 Citrate SOB TC Monomerlinker Mol. Eq. ing (mmol/g) (mmol/g) (mmol/g) (mmol/g) (mmol/g)(mmol/g) AAH DAEDA1 0.4 3.2 1.7 6.5 1.4 1.3 0.4 0.5 AAH DAPDA 0.3 2.72.0 6.6 1.9 1.9 0.4 0.4 AAH DAPDA 0.4 4.0 2.0 6.4 1.9 1.8 0.4 0.4 AAHDAPDA 0.6 4.5 2.0 6.3 1.5 1.3 0.4 0.6 AAH DAPDA 0.7 4.6 2.1 6.0 2.2 1.20.3 0.5 AAH DAPDA 0.5 4.8 2.0 6.3 1.9 1.4 0.4 0.5 AAH TAA 0.3 2.3 2.14.4 0.4 0.5 0.4 1.6 AAH TAA 0.3 3.4 2.1 4.9 0.3 0.4 0.3 1.8 AAH TAA 0.33.6 2.2 4.7 0.3 0.3 0.3 1.9 AAH/20% DAPDA Bead DCP 0.7 2.2 2.3 4.6 2.50.9 0.2 0.3 AAH/20% DAPDA Bead DCP 0.7 3.1 2.1 4.3 1.5 0.9 0.3 0.6AAH/20% DAPDA Bead DCP 0.3 3.2 1.9 5.3 1.0 1.1 0.4 1.0 AAH/20% DAPDABead DCP 0.5 3.2 2.1 4.9 1.2 0.9 0.3 0.6 AAH/20% DAPDA Bead DCP 0.7 3.22.2 4.7 1.4 0.8 0.3 0.4 AAH/20% DAPDA Bead DCP 0.7 3.5 2.1 4.3 1.5 0.80.3 0.6 AAH/25% DAPDA Bead DCP 0.7 2.2 2.3 4.3 2.1 0.9 0.3 0.4 AAH/25%DAPDA Bead DCP 0.7 2.8 2.1 4.8 1.5 0.7 0.3 0.5 AAH/25% DAPDA Bead DCP0.5 2.8 2.1 5.0 1.4 0.8 0.3 0.6 AAH/25% DAPDA Bead DCP 0.7 3.0 2.3 4.21.5 0.9 0.3 0.5 AAH/25% DAPDA Bead DCP 0.3 3.1 2.0 5.4 1.0 1.0 0.3 0.9C2A3BTA ECH 4.3 2.9 1.8 3.8 nm nm nm nm C2A3BTA ECH 5.3 3.1 1.6 3.5 nmnm nm nm C2A3BTA ECH 3.3 3.5 1.7 4.1 nm nm nm nm C2A3BTA ECH 4.8 3.7 1.64.0 nm nm nm nm C2A3G2 ECH 7.3 2.3 1.7 1.9 nm nm nm nm C2A3G2 ECH 4.32.4 1.7 3.7 nm nm nm nm C2PW BCPA 5.0 2.2 1.7 4.0 2.8 0.4 0.1 0.3 C2PWDC2OH 3.0 3.1 1.5 3.3 nm nm nm nm C2PW DC2OH 2.5 3.4 1.4 3.5 nm nm nm nmC2PW DC2OH 3.5 3.6 1.5 3.3 nm nm nm nm C2PW DC2OH 1.5 4.2 1.6 4.4 nm nmnm nm C2PW DCP 5.0 2.1 1.8 2.2 0.7 0.0 0.0 0.2 C2PW DCP 2.5 2.2 2.1 4.82.9 0.7 0.1 0.5 C2PW DCP 3.0 2.4 2.1 4.1 2.9 0.5 0.1 0.2 C2PW ECH 2.52.3 1.4 4.0 1.1 1.0 0.2 0.7 C3PW DCP 2.0 2.2 1.8 5.5 1.9 1.9 0.4 0.6C4A3BTA BCPA 5.0 2.3 2.2 4.7 2.6 0.8 0.2 0.5 C4A3BTA BCPA 3.0 3.4 2.15.7 2.7 0.8 0.2 0.5 C4A3BTA TGA 1.0 3.1 1.8 4.7 nm nm nm nm EDA1 DCP 2.02.5 1.6 3.6 1.1 0.5 0.1 0.7 EDA1 DCP 1.8 2.5 1.9 4.4 1.7 0.9 0.2 0.5EDA1 DCP 1.5 3.4 1.9 5.2 0.6 0.8 0.4 1.2 EDA1 ECH 2.0 3.5 1.3 3.4 nm nmnm nm EDA2 DCP 2.8 2.3 1.6 3.2 1.9 0.3 0.0 0.3 EDA2 DCP 2.3 2.5 1.8 3.62.4 0.3 0.0 0.3 EDA2 DCP 1.8 2.8 1.8 4.6 0.9 0.8 0.4 0.8 EDA3 BCPA 7.52.9 0.8 4.2 1.8 0.6 0.1 0.4 EDA3 BCPA 4.5 2.9 nm nm 2.0 0.3 0.0 0.2 EDA3BCPA 6.0 3.3 1.1 4.8 1.2 1.1 0.2 0.7 EDA3 BCPA 3.0 3.3 nm nm 2.0 0.4 0.00.3 EDA3 DCP 2.0 2.1 1.7 4.3 1.0 0.7 0.3 0.7 EDA3 DCP 3.5 2.5 2.2 3.21.7 0.3 0.1 0.4 EDA3 DCP 3.0 2.5 2.2 3.3 2.0 0.3 0.1 0.4 EDA3 DCP 2.52.9 2.2 4.1 1.8 0.5 0.1 0.6 EDA3 ECH 3.5 2.9 1.1 2.6 nm nm nm nm EDA3ECH 3.0 3.4 1.2 2.8 nm nm nm nm PAH/10% DC2OH Bead DCP 0.1 2.2 1.9 4.91.9 1.0 0.1 0.3 PAH/20% BCPA Bead DCP 0.7 2.7 3.1 6.4 4.8 0.7 0.1 0.2PDA1 BCPA 4.0 2.4 2.0 4.0 2.5 0.5 0.1 0.3 PDA1 BCPA 3.0 2.6 2.1 4.5 1.90.7 0.3 0.7 PDA1 DC2OH 2.0 3.5 1.2 2.9 nm nm nm nm PDA1 DCP 5.0 2.4 1.62.4 0.7 0.1 0.0 0.1 PDA1 DCP 6.0 2.9 1.3 2.1 0.4 0.1 0.0 0.4 PDA1 DCP1.8 4.1 2.2 6.3 0.8 1.4 0.5 1.7 PDA1 TGA 0.6 4.7 1.5 4.1 nm nm nm nmPDA2 ECH 2.5 2.7 1.5 3.2 nm nm nm nm PDA2 ECH 3.0 2.9 1.4 2.3 nm nm nmnm PDA2 ECH 1.5 3.2 1.6 3.3 nm nm nm nm Sevelamer DCP 0.7 3.6 1.7 4.81.4 1.3 0.4 0.9 Cl = Chloride; P: = Phosphate; TC = Taurocholate; nm =not measured

III. Screening Examples

The following examples illustrate means in which synthesized polymersmay be characterized by some of the screens defined above.

A. Quaternized Amine Assay

A QAA assay was performed with selected polymers. The data for the QAAassay for the control materials Dowex 1×8, a commercially available,crosslinked polystyrene bead containing fully quaternized amines thatwas obtained as the chloride salt and was subsequently converted to thenitrate salt for this study, are shown in Table 15. The data forAmberlite IRA67, a commercially available crosslinked acrylic beadcontaining tertiary amines that was obtained and used in this example asin the free amine form, are shown in the first two rows of Table 15. Asdemonstrated therein, the fully quaternized Dowex 1×8, as expected,bound equal quantities of chloride, specifically 1.8 mmol Cl/g, underthe acidic and basic pH conditions tested herein. Moreover, AmberliteIRA67, containing only tertiary amines, bound 5.9 mmol Cl/g under theacidic assay conditions employed, but bound ≤1.7% of this amount underthe basic conditions tested herein, at which the constituent amines aremostly deprotonated. Table 15 also shows the amount of chloride bindingby materials comprising C4A3BTA crosslinked with ECH at various moleequivalents of crosslinking agent. These materials, under the acidicconditions tested herein, demonstrate chloride binding >9 mmol Cl/g,frequently >10 mmol Cl/g, and under conditions of low crosslinking 13.4mmol Cl/g. These same materials, under the basic pH conditions testedherein, demonstrate chloride binding <0.8 mmol Cl/g, frequently <0.5mmol Cl/g, and under conditions of low crosslinking 0.3 mmol Cl/g. Underthe assay conditions employed, C4A3BTA crosslinked with 3.3 molequivalents of ECH demonstrated 1.9% amine quaternization, C4A3BTAcrosslinked with 4.3 mol equivalents of ECH demonstrated 2.2% aminequaternization, C4A3BTA crosslinked with 5.3 mol equivalents of ECHdemonstrated 6.2% amine quaternization, C4A3BTA crosslinked with 6.3 molequivalents of ECH demonstrates 4.5% amine quaternization, and C4A3BTAcrosslinked with 7.3 mol equivalents demonstrates 8.7% aminequaternization.

B. SOB Binding Kinetics

Selected polymers were evaluated in a SOB kinetic experiment, with anionbinding being evaluated at 2, 24, and 48 hours of incubation. The dataare described in Table 16. The bixalomer reference polymer prepared fromC4A3BTA as monomer and ECH as crosslinker at a crosslinker to monomerratio of 2.35 was shown to bind 0.8 mmol/g of chloride and 1.5 mmol/g ofphosphate at 2 hours. After 48 hours of incubation in the same buffer,chloride and phosphate binding decreased to 0.4 and 1.0 mmol/g,respectively, and taurocholate binding increased from 0.6 mmol/g at 2hours to 1.0 mmol/g at 48 hours. There was no change in citrate binding;this sample bound 0.5 mmol/g of citrate at 2 and 48 hours.

As shown in Table 16, a polymer prepared from C4A3BTA as a monomer andECH at a higher crosslinker to monomer ratio of 4.3 bound 3.0 mmol/g ofchloride and 0.2 mmol/g of phosphate at 2 hours. After 48 hours ofincubation in the same buffer, chloride binding decreased to 1.9 mmol/gand phosphate binding increased to 0.9 mmol/g. Taurocholate bindingincreased from 0.2 mmol/g at 2 hours to 0.4 mmol/g at 48 hours. Citratebinding was 0.0 mmol/g of citrate at 2 and 48 hours.

As shown in Table 16, a polymer prepared from C4A3BTA as a monomer andECH at an even higher crosslinker to monomer ratio of 7.3 was shown tobind 1.6 mmol/g of chloride and 0.6 mmol/g of phosphate at 2 hours.After 48 hours of incubation in the same buffer, chloride bindingdecreased to 1.2 mmol/g and phosphate binding increased to 1.0 mmol/g.Taurocholate binding was 0.0 mmol/g at 2 and 48 hours. Citrate bindingincreased from 0.0 mmol/g at 2 hours to 0.3 mmol/g at 48 hours.

C. Chloride Retention Assay

Selected polymers were evaluated for their ability to bind and retainchloride using the chloride retention assay (CRA). As shown in Table 17,Bixalomer reference polymer prepared from C4A3BT as monomer and ECH as acrosslinker at a crosslinker to monomer ratio of 2.35 was shown toinitially bind 0.86 mmol/g of chloride in SOB buffer. The polymer samplewas then allowed to incubate in a retention buffer (50 mM2-(N-morpholino)ethanesulfonic acid (MES), 100 mM sodium acetate, 5 mMsodium phosphate, 15 mM sulphate, adjusted to pH 6.2) for approximately40 hours at 37° C. followed by 16-20 hours incubation at 37° C. in anextraction solution (0.2 M sodium hydroxide). After extraction in 0.2 Msodium hydroxide, the sample was shown to have retained only 0.1 mmol/gof chloride ions that had bound in SOB, meaning the remaining chloridewas released during the retention buffer incubation and water washsteps.

As shown in Table 17 In the same chloride retention assay, anotherpolymer prepared from C4A3BTA as monomer and ECH as crosslinker at acrosslinker to monomer ratio of 5.3 was shown to initially bind 3.1mmol/g of chloride in SOB buffer. The 0.2 M sodium hydroxide extractionshowed that the sample retained 1.0 mmol/g of chloride with theremaining 2.1 mmol/g chloride having been released during the retentionbuffer incubation and water wash steps.

TABLE 15 QAA Results for Selected Commercial Reference and ExamplePolymers Crosslinker SGF-Cl BCS-Cl % Quaternary- Sample ID MonomerCrosslinker Eq. (mmol/g) (mmol/g) amines Dowex 1 × 8 Styrene DVB 8 1.81.8 100.0 Amberlite Acrylic NA NA 5.9 0.1 1.7 IRA67 010001-A2 C4A3BTAECH 3.3 13.4 0.3 1.9 010001-A3 C4A3BTA ECH 4.3 11.8 0.3 2.2 010001-A4C4A3BTA ECH 5.3 10.7 0.7 6.2 010001-A5 C4A3BTA ECH 6.3 10.0 0.4 4.5010001-A6 C4A3BTA ECH 7.3 9.2 0.8 8.7

TABLE 16 SOB binding kinetics SOB Cross- Swell Incu- SOB SOB SOB linker/SGF SIB Cl SIB P -ing bation Cl SOB P Citrate TC Cross- monomer (mmol/(mmol/ (mmol/ (gm/ time (mmol/ (mmol/ (mmol/ (mmol/ Amine linker ratiog) g) g) gm) (hrs) g) g) g) g) C4A3BTA ECH 2.35 12.8 1.7 5.2 2.3 2.0 0.81.5 0.5 0.6 24.0 0.6 1.2 0.5 0.9 48.0 0.4 1.0 0.5 1.0 C4A3BTA ECH 4.311.4 1.2 4.0 1.5 2.0 3.0 0.2 0.0 0.2 24.0 2.4 0.6 0.0 0.4 48.0 1.9 0.90.0 0.4 C4A3BTA ECH 7.3 8.2 0.6 2.9 1.2 2.0 1.6 0.6 0.0 0.0 24.0 1.4 1.00.2 0.0 48.0 1.2 1.0 0.3 0.0

TABLE 17 Chloride Retention Assay (CRA) Cross- linker/ Cross- monomerSGF SIB Cl SIB P Swelling Amine linker ratio (mmol/g) (mmol/g) (mmol/g)(gm/gm) Assay steps mmol/g C4A3BTA ECH 2.35 12.8 1.7 5.2 2.3 Chloridebound in 0.86 SOB buffer (mmol/g) Chloride released 0.37 in retentionbuffer (mmol/g) Chloride bound 0.1 after 0.2M extraction (mmol/g)C4A3BTA ECH 5.3 11.0 1.6 3.2 0.9 Chloride bound in 3.1 SOB buffer(mmol/g) Chloride released 1.95 in retention buffer (mmol/g) Chloridebound 1.02 after 0.2M extraction (mmol/g)

1. A method of treating metabolic acidosis in a patient, the methodcomprising orally administering to the patient a pharmaceuticalcomposition comprising a proton-binding, crosslinked amine polymercomprising the residue of an amine corresponding to Formula 1:

wherein R₁, R₂ and R₃ are independently hydrogen, hydrocarbyl,substituted hydrocarbyl provided, however, at least one of R₁, R₂ and R₃is other than hydrogen, the crosslinked amine polymer has an equilibriumswelling ratio in deionized water of less than 2, and the crosslinkedamine polymer has an equilibrium proton binding capacity and a chloridebinding capacity of at least 5 mmol/q in Simulated Gastric Fluid (“SGF”)containing 35 mM NaCl and 63 mM HCl at pH1.2 and 37° C. 2.-30.(canceled)
 31. The method of claim 1, wherein the crosslinked aminepolymer comprises the residue of an amine corresponding to Formula 1aand the crosslinked amine polymer is prepared by radical polymerizationof an amine corresponding to Formula 1a:

wherein R₄ and R₅ are independently hydrogen, hydrocarbyl, orsubstituted hydrocarbyl.
 32. The method of claim 31, wherein R₄ and R₅are independently hydrogen, aliphatic or heteroaliphatic.
 33. The methodof claim 1, wherein the patient is a human patient.
 34. The methodaccording to claim 1, wherein the serum bicarbonate is controlled ornormalized.
 35. The method according to claim 1, wherein thepharmaceutical composition is administered to the patient as a dailydose.
 36. The method according to claim 35, wherein the daily doseadministered is less than 20 g.
 37. The method according to claim 35,wherein the daily dose administered is less than 15 g.
 38. The methodaccording to claim 35, wherein the daily dose administered is less than10 g.
 39. The method according to claim 35, wherein the daily doseadministered is less than 5 g.
 40. The method according to claim 35,wherein the daily dose is administered once a day.
 41. The methodaccording to claim 35, wherein the daily dose results in a sustainedserum bicarbonate increase of ≥3 mEq/L.
 42. The method according toclaim 35, wherein a daily dose of 10 g or less per day results in anincrease in serum bicarbonate of ≥3 mEq/L.
 43. The method according toclaim 31, wherein the pharmaceutical composition is administered to thepatient as a daily dose.
 44. The method according to claim 43, whereinthe daily dose administered is less than 20 g.
 45. The method accordingto claim 43, wherein the daily dose administered is less than 15 g. 46.The method according to claim 43, wherein the daily dose administered isless than 10 g.
 47. The method according to claim 43, wherein the dailydose administered is less than 5 g.
 48. The method according to claim43, wherein the daily dose is administered once a day.
 49. The methodaccording to claim 43, wherein the daily dose results in a sustainedserum bicarbonate increase of ≥3 mEq/L.
 50. The method according toclaim 43, wherein a daily dose of 10 g or less per day results in anincrease in serum bicarbonate of ≥3 mEq/L.